中山大学蛋白质组学总结

I.Introduction

Structure

•Building blocks——amino acids

•Peptide bond and peptides

•Primary structure of protein

•The three-dimensional structure of proteins

•Getting protein structure

•Integral membrane proteins

•Relationship between structure and function of proteins

Function

•Principle in general

•Protein folding, misfolding and disease Regulation

* Expression

* Transportation&Localization

* Modification(Phosphorylation, glycosylation, methylation, acetylation, and ubiquitin)

* Interaction

* Degradation

Levels of structure

1°: Amino acid residue sequence

2°: Structural elements

3°: Specific 3-dimensional structure

4°: Arrangement of subunits in multi-subunit

protein

Note

• 16% N

• Met for metabolic labelling

• Trp, Tyr, and to a lesser extent Ph e, absorb

ultraviolet light. This accounts for the

characteristic strong absorbance of • light by

proteins at a wavelength of 280 nm.

• Count the amino acid numbers in

protein. 138 128 110

• symbol

•Nonstandard amino

acids (hydroxyproline,hydroxylysine)

•Some additional amino acids selenocysteine(硒半胱氨酸)andpyrrolysine(吡咯赖氨酸)

Chemical synthesis of peptides

• Liquid (Solution ) phase peptide synthesis • Solid phase peptide synthesis（SPPS）• Pre-treatment of amino acids

• Formation of peptide bond

• Deprotect, hydrolyze and purification Difference between biological and chemical synthesis of peptides

∙Template

∙Orientation 生物NC 化学CN

∙Efficiency (A protein with 100 amino acids : Chemical synthesis--about 4 days; Biological process--about 5 seconds in E. coli)

∙Condition

∙size

Sequence

∙Sanger 1953 胰岛素

∙反推DNA（简并性）

∙抗原抗体核糖体测mRNA

∙测一部分比对数据库

Motifs(units)

structure motifs

1) Helix-loop-helix2 αhelices joined by bridge

2) βhairpin2 adjacent antiparallel βstrands

connected by a β-turn.

3) β−α−βloopAn αhelix serves as the connection

between 2 parallel βstrands.

function motifs Thr-Gly-Tyr,Thr-Pro-Tyr motif Domains

1) All αdomainsrepeat of helix-loop-helix motif

2) All βdomainsrepeat of βhairpin gives

anti-parallel βstructures

3) α/ βdomainsrepeat of β−α−βmotif to give

parallel βstructures

4) α+ βdomainsThe α-helices and β-sheets are

relatively separate.

介于2级与三级结构 modular evolution union of new function

分子识别Molecular recognition

1.不同组分识别（四级结构）

2.内吞等受体、配体标记

3.抗原抗体

4.酶与底物、酶抑制剂

5.疫苗

地中海贫血