毕赤酵母诱导表达步骤
毕赤酵母的摇瓶发酵方法
毕赤酵母的摇瓶发酵方法：一、摇瓶发酵方法: 毕赤酵母摇瓶发酵方法分为两个阶段，1、酵母菌株生长阶段；2、脂肪酶诱导表达阶段。
1、酵母生长阶段。
准备试剂：1000ml BMGY培养基，1000ml BMM培养基，10X的甲醇，摇瓶1L （灭菌），温控摇床，50ml 离心管（灭菌）。
紫外分光光度计，石英比色皿。
以下所有操作均在超净台内或者无菌条件下完成。
（1）往灭好菌的IL摇瓶中加入100mlBMG培养基，然后加入约1ml脂肪酶菌株（培养基：菌液=100：1），用透气膜封口（透气，但是细菌不能透过）。
置于温控摇床上，温度调至300C，转速为250-300rpm/min，使酵母生长，OD600=2.0-6.0 ，时间约为15-24 小时。
（2）将发酵液转入50ml离心管，1500g-3000g离心5min。
去掉上清，用BMMY 培养基将菌体浓度稀释至OD0°=1.0，约有500ml左右。
将稀释后的发酵液分别加入到1L的药瓶中，每个摇瓶150ml发酵液（绝不能超过200ml）。
（3）将摇瓶置于温控摇床上，温度调至300C，转速为250-300rpm/min，使酵母表达脂肪酶，每24小时加入一次5%的甲醇，使甲醇的终浓度为0.5%。
连续诱导表达48 小时。
（4）将发酵液进行12000rpm/min离心5min，取上清（若上清仍混浊，可反复离心）；进行酶活分析和蛋白含量分析。
BMG培养基的配制（1000ml）: 20g蛋白胨（peptone）,10g酵母提取物（Yeast Extract）,加水至700ml; 121°C高温灭菌20min。
然后分别在无菌条件下加入10X YNB 100ml, 10X 磷酸钾缓冲液（PH6.0）100ml，10X甘油100ml。
BMM培养基的配制方法（1000ml）：20g蛋白胨（peptone）,10g酵母提取物，加水至700ml；1210C高温灭菌20min。
毕赤酵母实验操作手册
毕赤酵母表达实验手册大肠杆菌表达系统最突出的优点是工艺简单、产量高、生产成本低。
然而，许多蛋白质在翻译的修饰加工，如磷酸化、糖基化、酰胺化及蛋白酶水解等过程才能转化成活性形式。
大肠杆菌缺少适合用于表达结构复杂的蛋白质。
另外，蛋白质的活性还依赖于形成正确的二硫键并折叠成高级结表达的蛋白质往往不能进行正确的折叠，是以包含体状态存在。
包含体的形成虽然简化了产物的纯的活性，为了得到有活性的蛋白，就需要进行变性溶解及复性等操作，这一过程比较繁琐，同时增与大肠杆菌相比，酵母是低等真核生物，具有细胞生长快，易于培养，遗传操作简单等原核生物的生物时表达的蛋白质进行正确加工，修饰，合理的空间折叠等功能，非常有利于真核基因的表达，菌系统缺乏蛋白翻泽后加工、修饰的不足。
因此酵母表达系统受到越来越多的重视和利用。
大肠杆菌是用得最多、研究最成熟的基因工程表达系统，当前已商业化的基因工程产品大多是通过其主要优点是成本低、产量高、易于操作。
但大肠杆菌是原核生物，不具有真核生物的基因表达调加工修饰能力，其产物往住形成没有活性的包涵体，需要经过变性、复性等处理，才能应用。
近年程菌表达外源蛋白日益引起重视，主更是因为酵母是单细胞真核生物，不但具有大肠杆菌易操作、化生产的特点，还具有真核生物表达系统基因表达调控和蛋白修饰功能，避免了产物活性低，包涵间题［1］。
与大肠杆菌相比，酵母是单细胞真核生物，具有比较完备的基因表达调控机制和对表达产物的们对酿酒酵母（Saccharomyces.Cerevisiae）分子遗传学方面的认识最早，酿酒酵母也最先作为外宿主．1981年酿酒酵母表达了第一个外源基因一干扰素基因，随后又有一系列外源基因在该系统得素和胰岛素已大量生产并在人群中广泛应用，但很大部分表达由实验室扩展到工业规模时，培养基数的选择压力消失，质粒变得不稳定，拷贝数下降，而大多数外源基因的高效表达需要高拷贝数的量下降。
同时，实验室用培养基复杂而昂贵，采用工业规模能够接受的培养基时，往往导致产量的酵母的局限，人们发展了以甲基营养型酵母（methylotrophic yeast）为代表的第二代酵母表达系甲基营养型酵母包括：Pichia、Candida等．以Pichia.pastoris（毕赤巴斯德酵母）为宿主的外源来发展最为迅速，应用也最为广泛，已利用此系统表达了一系列有重要生物学活性的蛋自质。
毕赤酵母表达(pichia pastoris expression )实验手册(3)
毕赤酵母表达（pichia pastoris expression ）实验手册（3）液体YPD培养基可常温保存；琼脂YPD平板在4℃可保存几个月。
加入Ze ocin 100ug / ml，成为YPDZ培养基，可以4℃条件下保存1～2周。
2.4 YPDS + Zeocin 培养基（Yeast Extract Peptone Dextrose Medi um）：yeast extract 1%peptone 2%dextrose (glucose) 2%sorbitol 1 M+agar 2%+ Zeocin 100 μg/ml不管是液体 YPDS培养基，还是YPDS + Zeocin 培养基，都必须存放4℃条件下，有效期1～2周。
2.5 MGYMinimal Glycerol Medium （最小甘油培养基）（34%YNB；1%甘油；4*10-5%生物素）。
将800ml灭菌水、100ml的 10* YNB母液、2ml的500*B母液和100ml的10*GY母液混匀即可，4℃保存，保存期为2个月。
2.6 MGYHMinimal Glycerol Medium + Histidine （最小甘油培养基 + 0.004%组氨酸）在1000ml的MGY培养基中加入 10ml的100*H母液混匀，4℃保存，保存期为2个月。
2.7 RDRegeneration Dextrose Medium （葡萄糖再生培养基）（含有：1mol/L的山梨醇；2%葡萄糖；1.34%YNB；4*10-5%生物素；0. 005%氨基酸）1. 将186g的山梨醇定容至700ml，高压灭菌；2. 冷却后于45℃水浴；3. 将100ml的10*D、100ml的10*YNB；2ml的500*B；10ml的100*AA等母液和88ml无菌水混匀，预热至45℃后，与步骤2 的山梨醇溶液混合。
4℃保存。
2.8 RDHRegeneration Dextrose Medium + Histidine （葡萄糖再生培养基 + 0.004%组氨酸）在RD培养基配制的第三步中，在加入10ml的100*H母液，同时无菌水的体积减少至78ml即可，其余配制方法与RD相同。
毕赤酵母表达操作手册(精译版)
毕赤酵母多拷贝表达载体试剂盒用于在含多拷贝基因的毕赤酵母菌中表达并分离重组蛋白综述：基本特征：作为真核生物，毕赤酵母具有高等真核表达系统的许多优点：如蛋白加工、折叠、翻译后修饰等。
不仅如此，操作时与E.coli及酿酒酵母同样简单。
它比杆状病毒或哺乳动物组织培养等其它真核表达系统更快捷、简单、廉价，且表达水平更高。
同为酵母，毕赤酵母具有与酿酒酵母相似的分子及遗传操作优点，且它的外源蛋白表达水平是后者的十倍以至百倍。
这些使得毕赤酵母成为非常有用的蛋白表达系统。
与酿酒酵母相似技术：许多技术可以通用：互补转化基因置换基因破坏另外，在酿酒酵母中应用的术语也可用于毕赤酵母。
例如：HIS4基因都编码组氨酸脱氢酶；两者中基因产物有交叉互补；酿酒酵母中的一些野生型基因与毕赤酵母中的突变基因相互补，如HIS4、LEU2、ARG4、TR11、URA3等基因在毕赤酵母中都有各自相互补的突变基因。
毕赤酵母是甲醇营养型酵母：毕赤酵母是甲醇营养型酵母，可利用甲醇作为其唯一碳源。
甲醇代谢的第一步是：醇氧化酶利用氧分子将甲醇氧化为甲醛，还有过氧化氢。
为避免过氧化氢的毒性，甲醛代谢主要在一个特殊的细胞器－过氧化物酶体－里进行，使得有毒的副产物远离细胞其余组分。
由于醇氧化酶与O2的结合率较低，因而毕赤酵母代偿性地产生大量的酶。
而调控产生醇过氧化物酶的启动子也正是驱动外源基因在毕赤酵母中表达的启动子。
两种醇氧化酶蛋白：毕赤酵母中有两个基因编码醇氧化酶－AOX1及AOX2。
细胞中大多数的醇氧化酶是AOX1基因产物。
甲醇可紧密调节、诱导AOX1基因的高水平表达，较典型的是占可溶性蛋白的30%以上。
AOX1基因已被分离，含AOX1启动子的质粒可用来促进编码外源蛋白的目的基因的表达。
AOX2基因与AOX1基因有97%的同源性，但在甲醇中带AOX2基因的菌株比带AOX1基因菌株慢得多，通过这种甲醇利用缓慢表型可分离Muts菌株。
表达：AOX1基因的表达在转录水平受调控。
毕赤酵母内源蛋白表达系统 发酵优化策略
毕赤酵母内源蛋白表达系统发酵优化策略随着生物技术和生物医药行业的快速发展，蛋白表达成为了研究和生产领域中一个至关重要的环节。
毕赤酵母（Pichia pastoris）作为一种有效的真菌表达系统，被广泛应用于蛋白表达、酶制备等领域。
本文将从毕赤酵母内源蛋白表达系统的发酵优化策略进行探讨，以期为相关研究提供一定的参考和借鉴意义。
一、毕赤酵母内源蛋白表达系统简介毕赤酵母是一种酿酒酵母，具有真核生物和原核生物的特点，具有许多原核和真核表达系统的优点。
Pichia pastoris作为一种高效的真菌表达系统，广泛应用于蛋白质表达、酶制备、重组激素和疫苗生产、抗体工程等领域。
毕赤酵母在高密度、大规模表达的过程中具有许多优点，例如可以利用化石燃料产生的甲醇为碳源并利用氧化酶将甲醇作为能源，这使得它在蛋白质大规模表达中的应用有了很大的便利；其次methylotrophic yeast P.pastoris是一种易于操作的槽稠传播。
分泌蛋白在生成后由细胞外酶直接切割。
得到的目的蛋白质易纯化和分离。
由于其许多优点，毕赤酵母内源蛋白表达系统在生物技术和制药行业中受到极大的关注。
二、毕赤酵母内源蛋白表达系统的发酵优化策略（一）基础培养基的选择在毕赤酵母内源蛋白表达系统的发酵过程中，培养基的选择对于蛋白质的表达和纯化至关重要。
通常情况下，毕赤酵母内源蛋白表达系统常用的基础培养基包括YPG液体培养基、BMGY培养基和BMMY培养基。
其中，BMGY培养基在毕赤酵母的扩大培养和生长过程中被广泛应用，其主要成份包括酵母抽提物（yeast extract）、复合酵母粉（peptone）、甘油（glycerol）和缓冲盐溶液等。
而BMMY培养基主要用于毕赤酵母内源蛋白表达系统的诱导表达过程，其主要成份包括酵母醣（yeast extract）、蛋白胨（peptone）、抗泡剂（anti-foaming agent）以及甲醇（methanol）等。
猫血清白蛋白重组蛋白及其在毕赤酵母中的表达方法
猫血清白蛋白重组蛋白及其在毕赤酵母中的表达方法
猫血清白蛋白重组蛋白是一种重要的生物活性蛋白，具有多种生物学功能，如维持血浆渗透压、运输物质、免疫防御等。
在毕赤酵母中表达猫血清白蛋白重组蛋白，有助于研究该蛋白的结构和功能，并为生物制药、生物材料等领域提供重要资源。
猫血清白蛋白重组蛋白在毕赤酵母中的表达方法如下：
1. 基因克隆：首先从猫基因组数据库中获取猫血清白蛋白基因序列，通过 PCR 扩增得到目的基因。
然后，将目的基因与毕赤酵母的穿梭载体（如 pPICZα）进行重组，构建表达载体。
2. 转化毕赤酵母：将构建好的表达载体转化到毕赤酵母细胞中，通过筛选抗性平板得到转化子。
3. 诱导表达：在含有一定浓度诱导剂（如甲醇）的培养基中，培养转化子，诱导目的蛋白的表达。
甲醇诱导剂可以激活重组蛋白的表达，且在一定范围内，甲醇浓度越高，表达量也越高。
但过高的甲醇浓度会影响酵母的生长。
4. 蛋白纯化：诱导表达后的酵母细胞经过破碎、离心等步骤，获取含目的蛋白的的上清液。
然后，利用离子交换层析、凝胶过滤等方法对目的蛋白进行纯化。
5. 活性鉴定：对纯化的猫血清白蛋白重组蛋白进行活性鉴定，检测其在生理功能方面的表现，如抗氧化、抗炎等。
6. 应用：猫血清白蛋白重组蛋白在生物制药、生物材料等领域具有广泛应用前景。
例如，它可以作为生物制药的原料，用于治疗疾
病；也可以作为生物材料，用于组织工程和再生医学等。
总之，通过以上方法，可以在毕赤酵母中表达猫血清白蛋白重组蛋白，并进行纯化和活性鉴定。
这为研究猫血清白蛋白的结构和功能，以及将其应用于生物制药、生物材料等领域奠定了基础。
毕赤酵母实验操作手册
精心整理毕赤酵母表达实验手册大肠杆菌表达系统最突出的优点是工艺简单、产量高、生产成本低。
然而，许多蛋白质在翻译后，需经过翻译后的修饰加工，如磷酸化、糖基化、酰胺化及蛋白酶水解等过程才能转化成活性形式。
大肠杆菌缺少上述加工机制，不适合用于表达结构复杂的蛋白质。
另外，蛋白质的活性还依赖于形成正确的二硫键并折叠成高级核生物表达系统基因表达调控和蛋白修饰功能，避免了产物活性低，包涵体变性、复性等等间题［1］。
与大肠杆菌相比，酵母是单细胞真核生物，具有比较完备的基因表达调控机制和对表达产物的加工修饰能力，人们对酿酒酵母（Saccharomyces.Cerevisiae）分子遗传学方面的认识最早，酿酒酵母也最先作为外源基因表达的酵母宿主．1981年酿酒酵母表达了第一个外源基因一干扰素基因，随后又有一系列外源基因在该系统得到表达。
虽然干扰素和胰岛素已大量生产并在人群中广泛应用，但很大部分表达由实验室扩展到工业规模时，培养基中维特质粒高拷贝数的选择压力消失，质粒变得不稳定，拷贝数下降，而大多数外源基因的高效表达需要高拷贝数的维特，因此引起产量下降。
同时，实验室用培养基复杂而昂贵，采用工业规模能够接受的培养母（一。
⑷毕赤酵母中存在过氧化物酶体，表达的蛋白贮存其中，可免受蛋白酶的降解，而且减少对细胞的毒害作用。
Pichia.pastoris基因表达系统经过近十年发展，已基本成为较完善的外源基因表达系统，具有易于高密度发酵，表达基因稳定整合在宿主基因组中，能使产物有效分泌并适当糖基化，培养方便经济等特点。
利用强效可调控启动子AOX1，已高效表达了HBsAg、TNF、EGF、破伤风毒素C片段、基因工程抗体等多种外源基因，证实该系统为高效、实用、简便，以提高表达量并保持产物生物学活性为突出特征的外源基因表达系统，而且非常适宜子扩大为工业规模［4］。
目前美国FDA已能评价来自该系统的基因工程产品，最近来自该系统的Cephelon制剂已获得FDA批准，所以该系统被认为是安全的．Pichia.pastoris表达系统在生物工程领域将发挥越有中，需带有信号肽序列。
毕赤酵母表达手册(详细)
毕赤酵母表达（pichia pastoris expression ）实验手册2010-07-15 10:54:56| 分类：毕赤酵母| 标签：|字号大中小订阅一．毕赤酵母表达常用溶液及缓冲液的配制二．毕赤酵母表达的培养基配制三．主要试验环节的操作 3.1 酵母菌株的分离纯化 3.2 pPICZαA原核宿主菌TOP10F’的活化培养 3.3毕赤酵母表达的试验方法 3.4 毕赤酵母电转化方法 3.5 Pichia酵母表达直接PCR鉴定重组子的方法 3.6 毕赤酵母基因组提取方法 3.7 Mut+表型重组酵母的诱导表达实验关键词：酵母实验毕赤酵母表达 pichia pastoris expression 毕赤酵母酵母菌株大肠杆菌表达系统最突出的优点是工艺简单、产量高、周期短、生产成本低。
然而，许多蛋白质在翻译后，需经过翻译后的修饰加工，如磷酸化、糖基化、酰胺化及蛋白酶水解等过程才能转化成活性形式。
大肠杆菌缺少上述加工机制，不适合用于表达结构复杂的蛋白质。
另外，蛋白质的活性还依赖于形成正确的二硫键并折叠成高级结构，在大肠杆菌中表达的蛋白质往往不能进行正确的折叠，是以包含体状态存在。
包含体的形成虽然简化了产物的纯化，但不利于产物的活性，为了得到有活性的蛋白，就需要进行变性溶解及复性等操作，这一过程比较繁琐，同时增加了成本。
大肠杆菌是用得最多、研究最成熟的基因工程表达系统，当前已商业化的基因工程产品大多是通过大肠杆菌表达的，其主要优点是成本低、产量高、易于操作。
但大肠杆菌是原核生物，不具有真核生物的基因表达调控机制和蛋白质的加工修饰能力，其产物往住形成没有活性的包涵体，需要经过变性、复性等处理，才能应用。
近年来，以酵母作为工程菌表达外源蛋白日益引起重视，原因是与大肠杆菌相比，酵母是低等真核生物，除了具有细胞生长快，易于培养，遗传操作简单等原核生物的特点外，又具有真核生物时表达的蛋白质进行正确加工，修饰，合理的空间折叠等功能，非常有利于真核基因的表达，能有效克服大肠杆菌系统缺乏蛋白翻译后加工、修饰的不足。
毕赤酵母表达系统
毕赤酵母表达系统毕赤酵母表达系统前言：所用表达质粒有pPIC3.5K,pAO815用于胞内表达，而pPIC9K用于分泌表达，所有载体均利用AOX1启动子来诱导高水平表达。
抗性选择：最有效的筛选遗传霉素抗性及高抗性克隆的程序需要先对HIS＋转化子进行选择，再进行不同水平遗传霉素抗性筛选。
毕赤菌株表型：毕赤酵母菌GS115 及KM71 在组氨酸脱氢酶位点（His4）有突变,因而不能合成组氨酸，所有表达质粒都有HIS4 基因可与宿主进行互补，通过不含组氨酸的培养基来选择转化子。
GS115 及KM71都可在复合培养基如YPD（YEPD）及含组氨酸的最小培养基中生长。
转化之前，GS115 及KM71 都不能在最小培养基中生长，因为它们是His-。
培养温度：毕赤酵母生长温度为28-30度（液体、平板、斜面）。
在32 度以上诱导生长时，对蛋白表达有害，甚至会导致细胞死亡。
贮存：贮存细胞几周或几月，用YPD培养基或YPD 琼脂斜面1 挑取所需菌株单克隆在YPD 平板上划线生长；2 挑取单克隆转移至YPD进行穿刺培养，30 度2 天；3 细胞在4 度可放几周几月或几年，存于－80度1 挑取所需菌株单克隆在YPD 中过夜培养；2 收集细胞，在含15%甘油的YPD 中悬浮至终OD600 为50-100（大约2.5-5.0×109细胞/ml）；3 细胞先用液氮或干冰/酒精浴中冰冻再贮存于-80 度。
注意：在4 度或－80 度长期保存后，用之前建议在MM、MD 或MGY 平板上划线培养以检测His+转化子的表型是否正确及其活力。
以质粒pPIC9K，酵母Pichia pastoris GS115为例说明做法。
载体pPIC9K酶切为点线性化质粒DNA：建议使用下列方法线性化载体以获得Mut+及Muts重组子，可能其中一个会比另一个更利于表达多拷贝重组子。
如果只想得到Muts 重组子，使用KM71 菌株。
单个十字交换事件可比双重十字交换更容易、更有效地获得Muts 重组菌（例如：插入AOX1或his4 而不是取代AOX1）。
毕赤酵母表达手册
Pichia Expression KitVersion M01110225-0043Pichia Expression KitA Manual of Methods for Expression of Recombinant Proteins in Pichia pastorisCatalog no. K1710-01tech_service@iiINDIVIDUAL PICHIA EXPRESSION KIT LICENSE AGREEMENTThe Pichia Expression Kit is based on the yeast Pichia pastoris. Pichia pastoris was developed into an expression system by scientists at Salk Institute Biotechnology/Industry Associates (SIBIA) for high-level expression of recombinant proteins. All patents for Pichia pastoris and licenses for its use as an expression system are owned by Research Corporation Technologies, Inc. Tucson, Arizona. Invitrogen has an exclusive license to sell the Pichia Expression Kit to scientists for research purposes only, under the terms described below. Use of Pichia pastoris by commercial corporations requires the user to obtain a commercial license as detailed below. Before using the Pichia Expression Kit, please read the following license a greement. If you do not agree to be bound by its terms, contact Invitrogen within 10 days for authorization to return the unused Pichia Expression Kit and to receive a full credit. If you do agree to the terms of this Agreement, please complete the User Registration Card and return it to Invitrogen before using the kit.INDIVIDUAL PICHIA EXPRESSION KIT LICENSE AGREEMENTInvitrogen Corporation (INVITROGEN) grants you a non-exclusive license to use the enclosed Pichia Expression Kit (EXPRESSION KIT) for academic research or for evaluation purposes only. The EXPRESSION KIT is being transferred to you in furtherance of, and reliance on, such license. You may not use the EXPRESSION KIT, or the materials contained therein, for any commercial purpose without a license for such purpose from RESEARCH CORPORATION TECHNOLOGIES, INC., Tucson, Arizona. Commercial purposes include the use in or sale of expressed proteins as a commercial product, or use to facilitate or advance research or development of a commercial product. Commercial entities may conduct their evaluation for one year at which time this license automatically terminates. Commercial entities will be contacted by Research Corporation Technologies during the evaluation period regarding the purchase of a commercial license.Access to the EXPRESSION KIT must be limited solely to those officers, employees and students of your institution who need access thereto in order to perform the above-described research or evaluation. You must inform each of such officer, employee and student of the provisions of this Agreement and require them to agree, in writing, to be bound by the provisions of this Agreement. You may not distribute the EXPRESSION KIT to others, even those within your own institution. You may transfer modified, altered or original material from the EXPRESSION KIT to a third party following notification of INVITROGEN such that the recipient can be licensed. You may not assign, sub-license, rent lease or otherwise transfer this License or any of the rights or obligation hereunder, except as expressly permitted.This License is effective until terminated. You may terminate it at any time by destroying all Pichia expression products in your control. It will also terminate automatically if you fail to comply with the terms and conditions of the Agreement. You shall, upon termination of the License, destroy all Pichia Expression Kits in your control, and so notify INVITROGEN in writing.This License Shall be governed in its interpretation and enforcement by the laws of the State of California.Product User Registration CardPlease complete and return the enclosed Product User Registration Card for each Pichia Expression Kit that you purchase. This will serve as a record of your purchase and registration and will allow Invitrogen to provide you with technical support and manual updates. It will also allow Invitrogen to update you on future developments of and improvements to the Pichia Expression Kit. The agreement outlined above becomes effective upon our receipt of your User Registration Card or 10 days following the sale of the Pichia Expression Kit to you. Use of the kit at any time results in immediate obligation to the terms and conditions stated in this Agreement.Technical ServicesInvitrogen provides Technical Services to all of our registered Pichia Expression Kit users. Please contact us if you need assistance with the Pichia Expression Kit.United States Headquarters:Japanese Headquarters European Headquarters:Invitrogen Corporation1600 Faraday AvenueCarlsbad, CA 92008 USATel: 1 760 603 7200Tel (Toll Free): 1 800 955 6288 Fax: 1 760 602 6500E-mail:tech_service@ Invitrogen Japan K.K.Nihonbashi Hama-Cho Park Bldg. 4F2-35-4, Hama-Cho, NihonbashiTel: 81 3 3663 7972Fax: 81 3 3663 8242E-mail: jpinfo@Invitrogen Ltd3 Fountain DriveInchinnan Business ParkPaisley PA4 9RF, UKTel (Free Phone Orders): 0800 269 210Tel (General Enquiries): 0800 5345 5345Fax: +44 (0) 141 814 6287E-mail: eurotech@iiiivTable of ContentsMaterials (vii)Purchaser Notification (x)Product Qualification (xii)Introduction (1)Overview (1)Experimental Outline (3)Recombination and Integration in Pichia (7)Methods (11)Pichia Strains (11)E. coli Strains (13)Selecting a Pichia Expression Vector (14)pHIL-D2 (16)pPIC3.5 (17)pHIL-S1 (18)pPIC9 (19)Signal Sequence Processing (20)Cloning into the Pichia Expression Vectors (21)Transformation into E. coli (26)Preparation of Transforming DNA (27)Growth of Pichia for Spheroplasting (30)Preparation of Spheroplasts (32)Transformation of Pichia (34)Screening for Mut+ and Mut S Transformants (36)PCR Analysis of Pichia Integrants (40)Expression of Recombinant Pichia Strains (42)Analysis by SDS-Polyacrylamide Gel Electrophoresis (45)Optimization of Pichia Protein Expression (47)Scale-up of Expression (49)Protein Purification and Glycosylation (51)Recipes (53)E. coli Media Recipes (53)Pichia Media Recipes (54)Appendix (59)Electroporation of Pichia (59)PEG 1000 Transformation Method for Pichia (60)Lithium Chloride Transformation Method (61)Total DNA Isolation from Pichia (62)Detection of Multiple Integration Events (63)Procedure for Total RNA Isolation from Pichia (64)β-Galactosidase Assay (65)Technical Service (67)References (69)vviMaterialsKit Contents Box 1: Spheroplast Module. Store at room temperature.Reagent Amount ComponentsSOS media 20 ml 1 M Sorbitol0.3X YPD10 mM CaCl2Sterile Water 2 x 125 ml Autoclaved, deionized waterSE 2 x 125 ml 1 M Sorbitol25 mM EDTA, pH 8.0SCE 2 x 125 ml 1 M Sorbitol10 mM Sodium citrate buffer, pH 5.81 mM EDTA1 M Sorbitol2 x 125 ml --CaS 2 x 60 ml 1 M Sorbitol10 mM Tris-HCl, pH 7.5;10 mM CaCl240% PEG 25 ml 40% (w/v) PEG 3350 (Reagent grade) in waterCaT 25 ml 20 mM Tris-HCl, pH 7.520 mM CaCl2Stab Vials: Pichia and E. coli stabs. Store at +4°C.Phenotype(Pichia only)GenotypeStrain Amountstab his4Mut+GS115 1stab arg4 his4 aox1::ARG4 Mut S, Arg+KM71 1GS115 Albumin 1 stab HIS4Mut SGS115 β-Gal 1 stab HIS4Mut+stab F´ {pro AB, lac I q, lac Z∆M15, Tn10 (Tet R)} mcr A,TOP10F´ 1∆(mrr-hsd RMS-mcr BC), φ80lac Z∆M15, ∆lac X74,deo R, rec A1, ara D139, ∆(ara-leu)7697, gal U,gal K, rps L (Str R), end A1, nup G λ-.Box 2: Spheroplast Module. Store at -20°C.ComponentsReagent AmountZymolyase 10 x 20 µl 3 mg/ml Zymolyase in water(100,000 units/g lytic activity)1 M DTT 10 x 1 ml 1 M dithiothreitol in watercontinued on next pageviiKit Contents,continuedVector Box. Store at -20°C.Reagent DescriptionpHIL-D210 µg, lyophilized in TE, pH 8.0Vector for intracellular expression in PichiapPIC3.510 µg, lyophilized in TE, pH 8.0Vector for intracellular expression in PichiapHIL-S110 µg, lyophilized in TE, pH 8.0 Vector for secreted expression in Pichia. Uses the PHO1 signal sequencepPIC910 µg, lyophilized in TE, pH 8.0 Vector for secreted expression in Pichia. Uses the α-factor signal sequencePrimer Box. Store at -20°C.5´ AOX1 sequencing primer2 µg (312 pmoles), lyophilized5´-GACTGGTTCCAATTGACAAGC-3´3´ AOX1 sequencing primer2 µg (314 pmoles), lyophilized5´-GCAAATGGCATTCTGACATCC-3´α-Factor sequencing primer2 µg (315 pmoles), lyophilized5´-TACTATTGCCAGCATTGCTGC-3´Media The following prepackaged media is included for your convenience. Instructions for use are provided on the package.Media Amount Yield YP Base Medium 2 pouches 2 liters of YP mediumYP Base Agar Medium 2 pouches 2 liters of YP mediumYeast Nitrogen Base 1 pouch 500 ml of 10X YNBFor transformation of Pichia by spheroplasting, the Pichia Spheroplast Module isavailable separately from Invitrogen (see below for ordering information).Product Reactions or Amount Catalog no.Pichia Spheroplast Module 10 spheroplast preparations(50 transformations)K1720-01continued on next pageviiiRequired Equip-ment and Supplies (not provided) • 30°C rotary shaking incubator• Water baths capable of 37°C, 45°C, and 100°C• Centrifuge suitable for 50 ml conical tubes (floor or table-top)• Baffled culture flasks with metal covers (50 ml, 250 ml, 500 ml, 1000 ml, and 3 L)• 50 ml sterile, conical tubes• 6 ml and 15 ml sterile snap-top tubes (Falcon 2059 or similar)• UVSpectrophotometer• Mini agarose gel apparatus and buffers• Polyacrylamide Gel Electrophoresis apparatus and buffers• Media for transformation, growth, screening, and expression (see Recipes, pages 53-58) • 5% SDS solution (10 ml per transformation)• Sterile cheesecloth or gauze• Breaking Buffer (see Recipes, page 58)• Acid-washed glass beads (available from Sigma)• Replica-plating equipment (optional)• BeadBreaker™ (optional)ixPurchaser NotificationIntroduction The Pichia Expression Kit is based on the yeast Pichia pastoris. Pichia pastoris wasdeveloped into an expression system by scientists at Salk Institute Biotechnology/ IndustryAssociates (SIBIA) and Phillips Petroleum for high-level expression of recombinantproteins. All patents for Pichia pastoris and licenses for its use as an expression system areowned by Research Corporation Technologies (RCT), Inc., Tucson, Arizona. Forinformation on commercial licenses, please see page x.The Nature of the Invitrogen License Invitrogen has an exclusive license to sell the Pichia Expression Kit to scientists for research purposes only, under the terms described below. Use of Pichia pastoris by commercial entities for any commercial purpose requires the user to obtain a commercial license as detailed below. Before using the Pichia Expression Kit, please read the following license agreement. If you do not agree to be bound by its terms, contact Invitrogen within 10 days for authorization to return the unused Pichia Expression Kit and to receive a full credit. If you do agree to the terms of this license agreement, please complete the User Registration Card and return it to Invitrogen before using the kit.Pichia pastoris Patents Pichia pastoris is covered by one or more of the following U.S. patents and corresponding foreign patents owned and licensed by Research Corporation Technologies:4,683,293 4,808,537 4,812,405 4,818,700 4,837,148 4,855,231 4,857,467 4,879,231 4,882,279 4,885,242 4,895,800 4,929,555 5,002,876 5,004,688 5,032,516 5,122,465 5,135,868 5,166,329Individual Pichia Expression Kit License Agreement Invitrogen Corporation ("Invitrogen") grants you a non-exclusive license to use the enclosed Pichia Expression Kit ("Expression Kit") for academic research or for evaluation purposes only. The Expression Kit is being transferred to you in furtherance of, and reliance on, such license. You may not use the Expression Kit, or the materials contained therein, for any commercial purpose without a license for such purpose from Research Corporation Technologies, Inc., Tucson, Arizona.Definition of Commercial Purpose Commercial purposes include:(a) any use of Expression Products in a Commercial Product(b) any use of Expression Products in the manufacture of a Commercial Product(c) any sale of Expression Products(d) any use of Expression Products or the Expression Kit to facilitate or advanceresearch or development of a Commercial Product(e) any use of Expression Products or the Expression Kit to facilitate or advance anyresearch or development program the results of which will be applied to thedevelopment of Commercial Products"Expression Products" means products expressed with the Expression Kit, or with the use of any vectors or host strains in the Expression Kit. "Commercial Product" means any product intended for sale or commercial use.Commercial entities may conduct their evaluation for one year at which time this license automatically terminates. Research Corporation Technologies will contact commercial entities during the evaluation period regarding their desire for a commercial license.continued on next pagexPurchaser Notification, continuedIndividual Responsibilities Access to the Expression Kit must be limited solely to those officers, employees and students of your institution who need access to perform the above-described research or evaluation. You must inform each such officer, employee and student of the provisions of this license agreement and require them to agree, in writing, to be bound by the provisions of this license agreement. You may not distribute neither the Expression Kit nor the vectors or host strains contained in it to others, even to those within your own institution. You may only transfer modified, altered, or original material from the Expression Kit to a third party following written notification of, and written approval from, Invitrogen so that the recipient can be licensed. You may not assign, sub-license, rent, lease or otherwise transfer this license agreement or any of the rights or obligation thereunder, except as expressly permitted by Invitrogen and RCT.Termination of License This license agreement is effective until terminated. You may terminate it at any time by destroying all Pichia expression products in your control. It will also terminate auto-matically if you fail to comply with the terms and conditions of the license agreement. You shall, upon termination of the license agreement, destroy all Pichia Expression Kits in your control, and so notify Invitrogen in writing.This License shall be governed in its interpretation and enforcement by the laws of the State of California.Contact for Commercial Licensing Bennett Cohen, Ph.D.Research Corporation Technologies 101 North Wilmot Road, Suite 600 Tucson, Arizona 85711-3335 Phone: (520) 748-4400Fax: (520)748-0025User Registration Card Please complete and return the enclosed User Registration Card for each PichiaExpression Kit that you purchase. This will serve as a record of your purchase and regis-tration and will allow Invitrogen to provide you with technical support and manualupdates. It will also allow Invitrogen to update you on future developments and improve-ments to the Pichia Expression Kit. The agreement outlined above becomes effectiveupon our receipt of your User Registration Card or 10 days following the sale of thePichia Expression Kit to you. Use of the kit at any time results in immediate obligation tothe terms and conditions stated in this license agreement.xiProduct QualificationIntroduction This section describes the criteria used to qualify the components in the PichiaExpression Kit.Vectors All expression vectors are qualified by restriction enzyme digestion. Restriction digests must demonstrate the correct banding pattern when electrophoresed on an agarose gel.Spheroplast Reagents The spheroplast reagents are qualified by spheroplast preparation of GS115 following the protocol provided in the Pichia Expression Kit manual. At least 70% of the Pichia pastoris cells must form spheroplasts in 30 minutes or less.Pichia Strains The Pichia strains are by demonstrating viability of the culture. Single colonies should arise within 48 hours after streaking on YPD medium from the stabPrimers Sequencing primers are lot tested by automated DNA sequencing experiments.Buffers andSolutionsAll buffers and solutions are extensively tested for sterility.Media All Pichia growth and expression media are qualified by growing the GS115 Pichiastrain.xiiIntroductionOverviewReview Articles The information presented here is designed to give you a concise overview of the Pichia pastoris expression system. It is by no means exhaustive. For further information, pleaseread the articles cited in the text along with recent review articles (Buckholz and Gleeson,1991; Cregg et al., 1993; Sreekrishna et al., 1988; Wegner, 1990). A general review offoreign gene expression in yeast is also available (Romanos et al., 1992).General Characteristics of Pichia pastoris As a eukaryote, Pichia pastoris has many of the advantages of higher eukaryotic expression systems such as protein processing, protein folding, and posttranslational modification, while being as easy to manipulate as E. coli or Saccharomyces cerevisiae. It is faster, easier, and less expensive to use than other eukaryotic expression systems such as baculovirus or mammalian tissue culture, and generally gives higher expression levels. As a yeast, it shares the advantages of molecular and genetic manipulations with Saccharomyces, and has the added advantage of 10- to 100-fold higher heterologous protein expression levels. These features make Pichia very useful as a protein expression system.Similarity to Saccharomyces Many of the techniques developed for Saccharomyces may be applied to Pichia including: • transformation by complementation• genedisruption• genereplacementIn addition, the genetic nomenclature used for Saccharomyces has been applied to Pichia. For example, the HIS4 gene in both Saccharomyces and Pichia encodes histidinol dehydrogenase. There is also cross-complementation between gene products in both Saccharomyces and Pichia. Several wild-type genes from Saccharomyces complement comparable mutant genes in Pichia. Genes such as HIS4, LEU2, ARG4, TRP1, and URA3 all complement their respective mutant genes in Pichia.Pichia pastoris as a Methylotrophic Yeast Pichia pastoris is a methylotrophic yeast, capable of metabolizing methanol as its sole carbon source. The first step in the metabolism of methanol is the oxidation of methanol to formaldehyde using molecular oxygen by the enzyme alcohol oxidase. This reaction generates both formaldehyde and hydrogen peroxide. To avoid hydrogen peroxide toxicity, methanol metabolism takes place within a specialized cell organelle called the peroxisome, which sequesters toxic by-products from the rest of the cell. Alcohol oxidase has a poor affinity for O2, and Pichia pastoris compensates by generating large amounts of the enzyme. The promoter regulating the production of alcohol oxidase drives heterologous protein expression in Pichia.Two Alcohol Oxidase Proteins The AOX1 and AOX2 genes code for alcohol oxidase in Pichia pastoris. The AOX1 gene product accounts for the majority of alcohol oxidase activity in the cell. Expression of the AOX1 gene is tightly regulated and induced by methanol to high levels, typically > 30% ofthe total soluble protein in cells grown with methanol as the carbon source. The AOX1 gene has been isolated and the AOX1 promoter is used to drive expression of the gene of interest (Ellis et al., 1985; Koutz et al., 1989; Tschopp et al., 1987a). While AOX2 is about 97% homologous to AOX1, growth on methanol is much slower than with AOX1. This slowgrowth allows isolation of Mut S strains (aox1) (Cregg et al., 1989; Koutz et al., 1989).continued on next page1Overview, continuedExpression Expression of the AOX1 gene is controlled at the level of transcription. In methanol-grown cells approximately 5% of the polyA+ RNA is from the AOX1 gene. The regulation of theAOX1 gene is a two step process: a repression/derepression mechanism plus an inductionmechanism (e.g. GAL1 gene in Saccharomyces (Johnston, 1987)). Briefly, growth onglucose represses transcription, even in the presence of the inducer methanol. For thisreason, growth on glycerol is recommended for optimal induction with methanol. Pleasenote that growth on glycerol (derepression) is not sufficient to generate even minute levelsof expression from the AOX1 gene. The inducer, methanol, is necessary for detectablelevels of AOX1 expression (Ellis et al., 1985; Koutz et al., 1989; Tschopp et al., 1987a).Phenotype of aox1 mutants Loss of the AOX1 gene, and thus a loss of most of the cell's alcohol oxidase activity, results in a strain that is phenotypically Mut S (Methanol utilization slow). This has in the past been referred to as Mut. The Mut S designation has been chosen to accurately describe the phenotype of these mutants. This results in a reduction in the cells' ability to metabolize methanol. The cells, therefore, exhibit poor growth on methanol medium. Mut+ (Methanol utilization plus) refers to the wild type ability of strains to metabolize methanol as the sole carbon source. These two phenotypes are used when evaluating Pichia transformants for integration of your gene (Experimental Outline, page 3).Intracellular and Secretory Protein Expression Heterologous expression in Pichia can be either intracellular or secreted. Secretion requires the presence of a signal sequence on the expressed protein to target it to the secretory pathway. While several different secretion signal sequences have been used successfully, including the native secretion signal present on some heterologous proteins, success has been variable. The secretion signal sequence from the Saccharomyces cerevisiaeα factor prepro peptide has been used most successfully (Cregg et al., 1993; Scorer et al., 1993).The major advantage of expressing heterologous proteins as secreted proteins is that Pichia pastoris secretes very low levels of native proteins. That, combined with the very low amount of protein in the minimal Pichia growth medium, means that the secreted heterologous protein comprises the vast majority of the total protein in the medium and serves as the first step in purification of the protein (Barr et al., 1992). Note: If there are recognized glycosylation sites (Asn-X-Ser/Thr) in your protein's primary sequence, glycosylation may occur at these sites.Posttranslational Modifications In comparison to Saccharomyces cerevisiae, Pichia may have an advantage in the glyco-sylation of secreted proteins because it may not hyperglycosylate. Both Saccharomyces cerevisiae and Pichia pastoris have a majority of N-linked glycosylation of the high-mannose type; however, the length of the oligosaccharide chains added posttranslationally to proteins in Pichia (average 8-14 mannose residues per side chain) is much shorter than those in S. cerevisiae (50-150 mannose residues) (Grinna and Tschopp, 1989; Tschopp et al., 1987b). Very little O-linked glycosylation has been observed in Pichia.In addition, Saccharomyces cerevisiae core oligosaccharides have terminal α1,3 glycan linkages whereas Pichia pastoris does not. It is believed that the α1,3 glycan linkages in glycosylated proteins produced from Saccharomyces cerevisiae are primarily responsible for the hyper-antigenic nature of these proteins making them particularly unsuitable for therapeutic use. Although not proven, this is predicted to be less of a problem for glycoproteins generated in Pichia pastoris, because it may resemble the glycoprotein structure of higher eukaryotes (Cregg et al., 1993).2Experimental OutlineSelection of Vector and Cloning To utilize the strong, highly inducible P AOX1 promoter for expression of your protein, four expression vectors are included in this kit. pHIL-D2 and pPIC3.5 are used for intracellular expression while pHIL-S1 and pPIC9 are used for secreted expression (see pages 14-19 for more information). Before cloning your insert, you must...• decide whether you want intracellular or secreted expression.• analyze your insert for the following restriction sites: Sac I, Stu I, Sal I, Not I, and Bgl II. These sites are recommended for linearizing your construct prior to Pichiatransformation. If your insert has all of these sites, see pages 28-29 for alternate sites.Transformation and IntegrationTwo different phenotypic classes of His+ recombinant strains can be generated: Mut+ and Mut S. Mut S refers to the "Methanol utilization slow" phenotype caused by the loss of alcohol oxidase activity encoded by the AOX1 gene. A strain with a Mut S phenotype has a mutant aox1 locus, but is wild type for AOX2. This results in a slow growth phenotype on methanol medium. Transformation of strain GS115 can yield both classes of transformants, His+ Mut+ and His+Mut S, while KM71 yields only His+ Mut S since the strain itself is Mut S. Both Mut+ and Mut S recombinants are useful to have as one phenotype may favor better expression of your protein than the other. Due to clonal variation, you should test 6-10 recombinants per phenotype. There is no way to predict beforehand which construct or isolate will better express your protein. We strongly recommend that you analyze Pichia recombinants by PCR to confirm integration of your construct (see page 40).Once you have successfully cloned your gene, you will then linearize your plasmid to stimulate recombination when the plasmid is transformed into Pichia. The table below describes the types of recombinants you will get by selective digestion of your plasmid. RestrictionEnzymeIntegration Event GS115 Phenotype KM71 PhenotypeSal I or Stu I Insertion at his4His+ Mut+ His+ Mut SSac I Insertion at 5´AOX1 regionHis+ Mut+ His+ Mut SNot I or Bgl II Replacement atAOX1 locusHis+ Mut SHis+ Mut+His+ Mut S (notrecommended, see page 11)Expression and Scale-up After confirming your Pichia recombinants by PCR, you will test expression of both His+Mut+ and His+ Mut S recombinants. This will involve growing a small culture of each recombinant, inducing with methanol, and taking time points. If looking for intracellular expression, analyze the cell pellet from each time point by SDS polyacrylamide gel electrophoresis (SDS-PAGE). If looking for secreted expression, analyze both the cellpellet and supernatant from each time point. We recommend that you analyze your SDS-PAGE gels by both Coomassie staining and Western blot, if you have an antibody to your protein. We also suggest checking for protein activity by assay, if one is available. Not all proteins express to the level of grams per liter, so it is advisable to check by Western blotor activity assay, and not just by Coomassie staining of SDS-PAGE gels for production of your protein.Choose the Pichia recombinant strain that best expresses your protein and optimizeinduction based on the suggestions on pages 47-48. Once expression is optimized, scale-up your expression protocol to produce more protein.continued on next page3。
酵母表达系统步骤
酵母表达系统步骤毕赤酵母表达系统步骤（参考Invitrogen公司说明书）：一、pPICZαA、B、C质粒以及DH5α菌株的保存1取0.5μl pPICZα A、B、C质粒，热击转化DH5α，在低盐LB （含有25μg/ml Zeocin）的平板上37℃培养过夜。
2挑取转化子，甘油保存。
二、载体构建1将目的基因构建到pPICZα载体上，转化DH5α，用Zeocin筛选转化子。
2提质粒酶切鉴定或PCR鉴定3载体测序测序可用α-Factor引物或5’AOX1引物，3’AOX1引物三、线性化DNA1提取足够量的质粒DNA（一次转化至少需要5-10μg质粒）2 酶切线性化10μg构建好的载体，同时酶切空载体做对照，根据载体选择线性化酶切位点（样品分管酶切），pPICZα载体在5’AOX1区域有三个酶切位点可选择：SacI、PmeI、BstXI3 取1-2μl酶切产物跑电泳，确定是否酶切完全；4 过柱纯化线性化质粒（用50μl EB洗脱）；四、线性化DNA的去磷酸化处理线性化质粒43μlCIAP Buffer 5μlCIAP酶2μl四、总体积为50μl的样品37℃ 1h，过柱纯化，用30μl ddH2O 洗脱；五、感受态细胞的制备实验前准备：无抗性YPD平板一个、无抗生素液体YPD培养基，100μg/ml Zeocin YPD 平板和液体、50ml离心管两个、500ml预冷的无菌水、20ml 1M 山梨醇（灭菌预冷的），0.2cm预冷的电击杯；1YPD平板划线培养菌，30℃培养2-3d；250ml三角瓶中，加入5ml YPD，挑取酵母单菌落，30℃培养过夜；3吸取0.5ml菌液，加入至含有200ml新鲜YPD的1L三角瓶中，30℃，225rpm/min培养至OD值1.3-1.5；41500g，4℃离心5min收集菌体；540ml冰预冷的无菌水重悬沉淀；61500g，4℃,5min；730ml无菌水重悬；81500g，4℃,5min；910ml 1M 山梨醇重悬；101500g，4℃,5min；11加入1ml山梨醇，重悬冰上放置，直接做转化，或加入灭菌甘油每管80ul分装，冻存于-80℃(长时间保存会影响转化效率)；六、电击转化15-10μg线性化DNA（20μl<）与80ul上述感受态细胞混合，转移至预冷的0.2cm电击杯中（点击条件：电压1.5kV；电容25μF；电阻200Ω，电击时间为4～10msec）；2冰上放置5min3电击（按生产厂商提供的适合酵母用的参数）4迅速加入1ml预冷的1M 山梨醇，转移至1.5ml EP管中530℃静置培养1-2h（如果要增加存活率，获得更多的转化克隆，可在30℃静置培养1h后，加入1mlYPD培养基，30℃200rpm培养1h后取部分涂布与不同浓度抗生素的平板）6取50、100、200ul分别涂布于含有Zeocin的YPD平板，30℃培养2-10 d至有菌落出现；7如果要筛选多拷贝转化子，将转化克隆混合在一起，涂布在Zeocin 浓度为500、1000、2000μg/ml的YPD平板，培养2-3d。
毕赤酵母表达知识
很好，需要好好研究一下原文地址：毕赤酵母表达知识01转载于丁香作者：思时尔非a.配制500×BIOTIN stock solution（0.02％）有这么3种方案：1、懒人是将Biotin直接溶在去离子水中，放过夜，基本就能溶；2、急性子是将溶液配成0.02N的NaOH，就很容易溶解了；3、水浴加热，温度不能高于50度。
D－生物素是具有生物活性的生物素，也就是vitaminH。
在毕赤酵母代谢过程中，作为多种酶的辅基起作用。
天然培养基中一般可以不单独添加，因为YNB中、酵母粉、蛋白胨中均含有一定量的生物素，但是做高密度发酵还是必须要添加的。
b.有几个比较迷惑的问题请教大家：(很典型的小问题）1、制感受态细胞，OD多少比较好？pyrimidine 战友的方法：取1mlGS115过夜培养物(OD约6-10) 分装到1.5ml EP 管中。
说明书还有一些文献是说在1.3左右效率高，再高了效率会很低2、关于高效转化法，文献说用(LiAc)，而invitrogen的说明书说转化毕赤酵母用(LiAc)没用，要用LiCl。
Lithium acetate does not work with Pichia pastoris. Use only lithium chloride.3、YNB到底能高温灭么？有的说能有的说不能。
过滤灭菌的怎么操作？我是把滤器装好膜绑到瓶口用纱布盖上，报纸包上，瓶盖放烧杯里单灭。
然后把配好的溶液用注射器一点点推进去。
4、葡萄糖为什么在YPD里一起灭颜色很深，单灭则不会。
该115度还是121度灭？网上搜了下，都有人用！5、电转化参数用400欧还是200欧？有的用400，有的还专门说不是用400。
都是从园里看到的！电击参数：1.5KV，25uF，200欧姆（不是400）6、电转后，在MD平板上长的应该就是整合了目的基因的重组子了吧？如果不想筛高拷贝的，是否PCR验证一下即可？网友的回答：ynb最好不灭菌，我是0.22um过滤处理的。
毕赤酵母诱导表达实验步骤(1)
BMGY的配制（每200 mL）
Yeast extract 2 g
Peptone 4 g
K3PO4(pH 6.0) 20 mL
丙三醇 2 mL
定容至180 mL，121，灭20 min。
使用前再加入
10*YNB 20 mL（10%）（过滤除菌）
生物素0.4 mL（0.02%）（过滤除菌）
加入后，用紫外照射10 min左右再接菌。
BMMY的配制（每200 mL）
Yeast extract 2 g
Peptone 4 g
K3PO4(pH 6.0) 20 mL
定容至180 mL，121，灭20 min。
使用前再加入
10*YNB 20 mL（10%）（过滤除菌）
生物素0.4 mL（0.02%）（过滤除菌）
甲醇0.5%
加入后，用紫外照射10 min左右再接菌。
10*YNB的配制
酵母基础氮源培养基 3.4 g
硫酸铵10 g
双蒸水80 mL
定容至100 mL，过滤除菌（用0.22 μm滤膜过滤）。
毕赤酵母诱导表达
1.配BMGY和BMMY灭菌
2.使用前向BMGY按比例加入生物素、10*YNB，紫外照10 min。
3.接菌于BMGY，250 rpm，28℃摇24 h
4.向BMMY中按比例加入生物素、10*YNB、甲醇，紫外照10 min。
5.将含有菌液的BMGY转移至50 mL离心管，4℃5000 rpm 离心5 min，弃上
清。
6.用BMMY将沉淀菌体重悬，倒回瓶中，250 rpm，28℃，摇3 d。
每24 h补
一次甲醇。
毕赤酵母表达蛋白糖基化位点的方法
一、概述毕赤酵母是一种常见的真菌，它在生物技术和分子生物学领域有着广泛的应用。
在这些领域，研究人员经常需要对蛋白质进行糖基化修饰的研究，而毕赤酵母表达系统正是其中的一种重要工具。
本文将就毕赤酵母表达蛋白糖基化位点的方法进行介绍。
二、毕赤酵母表达系统简介1. 毕赤酵母表达系统的原理毕赤酵母表达系统是指利用毕赤酵母表达载体，将目标蛋白基因导入毕赤酵母中，使其在毕赤酵母中进行表达。
该系统具有高度的复制和表达效率，能够在较短的时间内高效地产生目标蛋白。
2. 毕赤酵母表达系统的优势和应用毕赤酵母表达系统具有许多优势，例如能够进行大规模的表达，提高了蛋白质的产量；同时也能够实现正常的翻译后修饰以及蛋白折叠功能。
在生物技术和分子生物学领域有着广泛的应用，如药物开发、生物能源等领域。
三、毕赤酵母表达蛋白糖基化位点的方法1. 利用质粒表达毕赤酵母表达载体中含有丰富的糖基化因子，对于糖基化位点的研究提供了便利。
研究人员可以将目标蛋白基因克隆至毕赤酵母表达载体中，通过大规模的表达筛选，筛选出糖基化位点进行研究。
2. 利用质粒诱导表达研究人员还可以通过对毕赤酵母进行质粒诱导，使其表达特定的糖基化酶，从而实现对特定蛋白质的糖基化位点的研究。
这种方法能够有效地降低研究成本，是当前常用的研究手段之一。
3. 基因敲除或过表达最近，基因敲除或过表达技术在毕赤酵母的研究中得到了广泛的应用。
研究人员可以通过敲除特定的糖基化酶基因或过表达其基因，从而实现对糖基化位点的研究。
这种方法能够帮助研究人员更深入地了解糖基化位点在蛋白质功能中的作用。
四、毕赤酵母表达蛋白糖基化位点研究的意义1. 为蛋白质功能研究提供重要依据研究糖基化位点能够帮助人们更深入地了解蛋白质的结构和功能。
糖基化位点通常与蛋白质的功能密切相关，通过研究糖基化位点，可以为蛋白质功能的研究提供重要的依据。
2. 为药物研发提供理论支持糖基化位点在药物研发中也有着重要的意义。
许多药物的研发过程中需要考虑蛋白质的糖基化修饰，因此对糖基化位点进行研究能够为药物研发提供理论支持。
酵母表达步骤整理
1、将鉴定正确的重组质粒新鲜摇菌，提质粒，单酶切线性化。
2、与此同时制备感受态细胞。
A、将划线培养的毕赤酵母GS115单菌落接种于3mL YPD培养基中，28°250r/min振荡培养24~48h；B、取培养物100uL转接于20mL YPD培养基中，28°振荡过夜，OD600=1.3~1.5时，1500r/min，4°，离心15min收获细胞；C、弃上清，加冰预冷的无菌蒸馏水洗沉淀，同上条件离心，重复两次（100mL水，50mL 水或50mL水，20mL水）；D、弃上清，加入冰预冷的1M的山梨醇洗涤，离心，条件同上，20mL；E、用0.8mL左右的冰预冷的1M的山梨醇悬浮菌体，置冰浴备用。
3、电转化A、取线性化的重组载体10uL与80uL感受态细胞混匀，然后转移到冰预冷的电转杯中，冰上放置5min；B、将电转杯放在电穿孔仪上用脉冲电流电击一次，条件：电压1500V，电容25uF，电阻200Ω，时间5ms；C、电击结束，立即加入1mL冰预冷的1M山梨醇，混匀，取250uL转化物涂于营养缺陷型MD培养基平皿，28°恒温培养2~4d（下垫湿纱布）。
4、表达A、从MD板子上挑取大的菌落转至96孔板中，每孔加入200~250uL YPD进行筛选；B、将最终筛出的孔混匀，取2uL滴在事先画好格的G418平板上，28°培养3d；C、将最终能在G418板上生长的菌落转至BMGY培养基中，28°摇16~18h，离心收集菌体沉淀；D、将菌体沉淀转至BMMY培养基中诱导表达，每24h补充甲醇一次，分别诱导24h、48h、72h、96h、120h；E、SDS-PAGE观察表达情况：将表达菌经12 000rpm/min，10min离心，取200uL上清加1mL丙酮沉淀（-20°，过夜），离心后尽弃上清，沉淀加25uL水溶解后加入loading buffer，电泳检测表达情况。
毕赤酵母表达知识
很好，需要好好研究一下原文地址：毕赤酵母表达知识01转载于丁香作者：思时尔非a.配制500×BIOTIN stock solution（0.02％）有这么3种方案：1、懒人是将Biotin直接溶在去离子水中，放过夜，基本就能溶；2、急性子是将溶液配成0.02N的NaOH，就很容易溶解了；3、水浴加热，温度不能高于50度。
D－生物素是具有生物活性的生物素，也就是vitaminH。
在毕赤酵母代谢过程中，作为多种酶的辅基起作用。
天然培养基中一般可以不单独添加，因为YNB中、酵母粉、蛋白胨中均含有一定量的生物素，但是做高密度发酵还是必须要添加的。
b.有几个比较迷惑的问题请教大家：(很典型的小问题）1、制感受态细胞，OD多少比较好？pyrimidine 战友的方法：取1mlGS115过夜培养物(OD约6-10) 分装到1.5ml EP 管中。
说明书还有一些文献是说在1.3左右效率高，再高了效率会很低2、关于高效转化法，文献说用(LiAc)，而invitrogen的说明书说转化毕赤酵母用(LiAc)没用，要用LiCl。
Lithium acetate does not work with Pichia pastoris. Use only lithium chloride.3、YNB到底能高温灭么？有的说能有的说不能。
过滤灭菌的怎么操作？我是把滤器装好膜绑到瓶口用纱布盖上，报纸包上，瓶盖放烧杯里单灭。
然后把配好的溶液用注射器一点点推进去。
4、葡萄糖为什么在YPD里一起灭颜色很深，单灭则不会。
该115度还是121度灭？网上搜了下，都有人用！5、电转化参数用400欧还是200欧？有的用400，有的还专门说不是用400。
都是从园里看到的！电击参数：1.5KV，25uF，200欧姆（不是400）6、电转后，在MD平板上长的应该就是整合了目的基因的重组子了吧？如果不想筛高拷贝的，是否PCR验证一下即可？网友的回答：ynb最好不灭菌，我是0.22um过滤处理的。
毕赤酵母发酵手册
毕赤酵母发酵手册总览简介：毕赤酵母和酿酒酵母很相似，都非常适合发酵生长。
毕赤酵母在有可能提高总体的蛋白质产量的发酵中能够达到非常高的细胞浓度，我们建议只有那些有过发酵经验或者能得到有经验的人的指导的人参与发酵。
因为发酵的类型很多，所以我们很难为您的个人案例提高详细的过程。
下面+s两种基因型的毕赤酵母菌株在15L的台式玻璃所给出的指导是基于MutMut和发酵罐中发酵而成。
请在您的发酵开始前先阅读操作员手册。
下面所给出的表就是整个发酵参数：在整个发酵过程中监测和调控下列参数非常重要。
下面的表格描述了这些参数和※设备推荐：下面是所推荐设备的清单：·发酵罐的夹套需要在发酵过程中给酵母菌降温，尤其是在甲醇流加过程中。
你需要一个固定的来源来提供冷却水（5-10℃）。
这可能意味着你需要一个冷冻装置来保持水的冷却。
·一个泡沫探针就像消泡剂一样不可或缺。
·一个氧气的来源——空气（不锈钢的发酵罐需要1-2vvm）或者纯氧（玻璃发酵罐需要0.1-0.3vvm）。
·添加甘油和甲醇的补料泵。
·pH的自动控制。
培养基的准备：你需要准确配置下列溶液：·发酵所需的基本盐类（第11页）·PTM补充盐类（第11页）1·75ml的50％的甘油每升初始发酵液，12ml的PTM补充盐每升甘油。
1·740ml的100％的甲醇每升初始发酵液，12ml的PTM补充盐每升甲醇。
1毕赤酵母生长的测定：在不同的时间点通过测OD600的吸光值和湿细胞的重量来检测毕赤酵母的生长。
培养的代谢速率通过通过观察溶氧浓度对应于有效碳源来测定。
溶氧的测定：简介：溶解氧的浓度时指氧气在培养基中的相关比例，溶氧100％是指培养基中氧达到饱和。
毕赤酵母的生长需要消耗氧气，减少溶解氧的满度。
毕赤酵母在生长时会消耗氧气，减少溶氧的程度。
然而，因为代谢甲醇的最初阶段需要氧气，所以将溶氧浓度维持在一个适当的水平（＞20％）来确保毕赤酵母在甲醇上的生长就至关重要。