《分子生物学》PPT课件 (2)

1.3 Protein Structure and
1.3 蛋白质的结构与
Function: A Few Examples
功能：几个例子
1.4 The Dynamics of Proteins 1.4 蛋白质动力学
1.5 Experiments
1.5 实验研究
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Chapter 1 Amino Acids to Proteins
✓Any amino acid can join to any other amino acid. ✓Proteins can be composed of any combination of
twenty amino acids, in any number and in any order.
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Glycine
甘氨酸
Gly G
Alanine
丙氨酸
Ala A
Isoleucine 异亮氨酸 Ile I
Leucine
亮氨酸
Leu L
Methionine 甲硫氨酸 Met M
Phenylalanine 苯丙氨酸 Phe F
Tryptophan 色氨酸
Trp W
Proline
脯氨酸
Pro P
Valine
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➢The twenty amino acids and abbreviation
They can be divided into four groups according to the property of their R groups.
9 Hydrophobic R groups 疏水的R基团
生命几乎就是蛋白质 的杰作。蛋白质让生 物可以生长和繁殖。 它们为生物提供了外 形和力量，以及运动 功能。 在细胞中，蛋白质无 处不在，行使着几乎 任何功能。
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萤火虫的荧光素酶消耗ATP催化底物发光
红细胞含有大量携氧的血红蛋白
犀牛是唯一的一种具有完全由角蛋白组 成角的动物。
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1.1 Protein Composition@
➢The formation of a peptide bond
The carboxyl group of one amino acid can react with the amino group of another amino acid to form a peptide bond(amide bond-酰胺键).
缬氨酸
Val V
2 Acidic R groups 酸性的R基团
Aspartic acid 天冬氨酸 Asp D
Glutamic acid 谷氨酸
Glu E
6 Hydrophilic R groups 亲水的R基团
Serine
丝氨酸
Ser S
Threonine 苏氨酸
Thr T
Asparagine 天冬酰胺 Asn N
Glutamine 谷氨酰胺 Gln Q
Cysteine
半胱氨酸 Cys C
Tyrosine
酪氨酸
Tyr Y
3 Basic R groups 碱性的R基团
Arginine
精氨酸
Arg R
Histidine
组氨酸
His H
Lysine
赖氨酸
Lys K
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✓Structures of hydrophobic amino acids
Life is most directly the work of proteins. Proteins allow organisms to grow and reproduce. They provide shape, strength and movement. In the cell, proteins are everywhere and do almost everything.
➢Proteins are composed of small molecules called
amino acids. Carbon atom attachs to four different chemical groups.
hydrogen atom
R group
Different amino acids have different R groups.
咪唑基
acidic R groups
胍基 basic R groups
Negative charge
PositivLeabharlann chargeAsp and Glu carry negative charges,Lys, Arg and His carry
positive charges at physiological pH value (7.2~7.6).
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➢20种氨基酸三字符必需记住：
• Ala Arg Asp Asn Cys Glu Gln Gly His Ile 丙 精 天 酰氨 半 谷 酰氨 甘 组 异亮
• Leu Lys Met Phe Pro Ser Thr Trp Tyr Val 亮 赖 甲硫 苯丙 脯 丝 苏 色 酪 缬
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脂 肪族和芳香族支链 维持蛋白质三维结构中起着重要作用（蛋白质的疏水核心）
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✓Structures of the hydrophilic amino acids
这类氨基酸的侧链都能与水形成氢键，因此易溶于水。 R基团有极性但一般不解离。
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✓Structures of acidic and basic amino acids
Chapter 1 Amino Acids to Proteins 从氨基酸到蛋白质
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Chapter 1 Amino Acids to Proteins
1.1 Protein Composition
1.1 蛋白质的组成
1.2 Protein Conformations
1.2 蛋白质的构象
✓Character of peptide bond：
Partial double bond / 部分双键
Double-bond joining the carbon and oxygen is also distributed between the same carbon and the adjacent nitrogen. This means that the peptide bond exists as an intermediate between a single bond and double bond.