《第十一章蛋白质生的物合成文档资料》由会员分享，可在线阅读，更多相关《第十一章蛋白质生的物合成文档资料（69页珍藏版）》请在金锄头文库上搜索。
1、蛋白质蛋白质的生物合成的生物合成Protein BiosynthesisEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.本章内容第一节第一节 蛋白质生物合成体系蛋白质生物合成体系 第二节第二节
2、 蛋白质生物合成过程蛋白质生物合成过程 第三节第三节 蛋白质合成后加工和输送蛋白质合成后加工和输送 第四节第四节 蛋白质生物合成的干扰和抑制蛋白质生物合成的干扰和抑制 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Asp
3、ose Pty Ltd. 蛋白质的生物合成蛋白质的生物合成，即，即翻译翻译，就是将核酸，就是将核酸中由中由 4 种种核苷酸序列核苷酸序列编码的遗传信息，通编码的遗传信息，通过过遗传密码遗传密码破译的方式解读为蛋白质一级破译的方式解读为蛋白质一级结构中结构中20种种氨基酸的排列顺序氨基酸的排列顺序 。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.
4、Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.蛋白质合成体系蛋白质合成体系第一节第一节Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright
5、 2004-2011 Aspose Pty Ltd.n n2020种氨基酸种氨基酸种氨基酸种氨基酸(AA)(AA)作为原料作为原料作为原料作为原料n n酶及众多蛋白因子，如酶及众多蛋白因子，如酶及众多蛋白因子，如酶及众多蛋白因子，如IFIF、eIFeIF n nATPATP、GTPGTP、无机离子、无机离子、无机离子、无机离子参与蛋白质生物合成的物质包括参与蛋白质生物合成的物质包括l 三种三种RNAmRNA（messenger RNA, 信使信使RNA）rRNA（ribosomal RNA, 核糖体核糖体RNA）tRNA（transfer RNA, 转移转移RNA）Evaluation onl
6、y.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.一、一、翻译模板翻译模板mRNA及遗传密码及遗传密码（一）（一） mRNA是遗传信息的携带者是遗传信息的携带者n遗传学将编码一个多肽的遗传单位称为顺遗传学将编码一个多肽的遗
7、传单位称为顺反子反子(cistron)。n原核细胞中数个结构基因常串联为一个转原核细胞中数个结构基因常串联为一个转录单位，转录生成的录单位，转录生成的mRNA可编码几种功可编码几种功能相关的蛋白质，为多顺反子能相关的蛋白质，为多顺反子(polycistron)。n真核真核mRNA只编码一种蛋白质，为单顺反只编码一种蛋白质，为单顺反子子(single cistron) 。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.
8、Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.原核生物的多顺反子原核生物的多顺反子真核生物的单顺反子真核生物的单顺反子非编码序列非编码序列核蛋白体结合位点核蛋白体结合位点起始密码子起始密码子终止密码子终止密码子编码序列编码序列PPP5 3 蛋白质蛋白质PPPmG -5 3 蛋白质蛋白质Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Pro
9、file 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（二）（二） mRNA上存在遗传密码上存在遗传密码 mRNA分分 子子 上上 从从 5 至至 3 方方 向向 ， 由由AUG开开始始，每每3个个核核苷苷酸酸为为一一组组，决决定定肽肽链链上上某某一一个个氨氨基基酸酸或或蛋蛋白白质质合合成成的的起起始始、终终止信号，称为三联体密
10、码止信号，称为三联体密码(triplet coden)。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.遗传密码表目目 录录Evaluation only.Created with Aspos
11、e.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.从从mRNA 5 端端起起始始密密码码子子AUG到到3 端端终终止止密密码码子子之之间间的的核核苷苷酸酸序序列列，各各个个三三联联体体密密码码连连续续排排列列编编码码一一个个蛋蛋白白质质多多肽肽链链，称称为为开开
12、放放阅阅读读框框架架(open reading frame, ORF)。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（三）遗传密码的特点（三）遗传密码的特点 1.连续性连续性(comma
13、less) 编码蛋白质氨基酸序列的各个三联体密编码蛋白质氨基酸序列的各个三联体密码连续阅读，密码间既无间断也无交叉。码连续阅读，密码间既无间断也无交叉。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty
14、 Ltd.基因损伤引起基因损伤引起mRNA阅读框架内的碱基发生阅读框架内的碱基发生插入或缺失，可能导致框移突变插入或缺失，可能导致框移突变(frameshift mutation)。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-
15、2011 Aspose Pty Ltd.2.简并性简并性(degeneracy)遗传密码中，除色氨酸和甲硫氨酸仅有一个遗传密码中，除色氨酸和甲硫氨酸仅有一个密码子外，其余氨基酸有密码子外，其余氨基酸有2、3、4个或多至个或多至6个三联体为其编码。个三联体为其编码。起始密码子：起始密码子：AUG终止密码子：终止密码子：UAA, UAG, UGAEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation onl
16、y.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyrig
17、ht 2004-2011 Aspose Pty Ltd.3.通用性通用性(universal)n蛋白质生物合成的整套密码，从原核生物蛋白质生物合成的整套密码，从原核生物到人类都通用。到人类都通用。 n已发现少数例外，如动物细胞的线粒体、已发现少数例外，如动物细胞的线粒体、植物细胞的叶绿体。植物细胞的叶绿体。n密码的通用性进一步证明各种生物进化自密码的通用性进一步证明各种生物进化自同一祖先。同一祖先。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011
18、 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.4.摆动性摆动性(wobble) 转转运运氨氨基基酸酸的的tRNA的的反反密密码码需需要要通通过过碱碱基基互互补补与与mRNA上上的的遗遗传传密密码码反反向向配配对对结结合合，但但反反密密码码子子第第一一位位与与密密码码子子第第三三位位间间不不严严格格遵遵守守常常见见的的碱碱基基配配对对规规律律，称称为为摆动配对。摆动配对。 Evalua
19、tion only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.密码子、反密码子配对的摆动现象tRNA反密码子第1位碱基IUGACmRNA密码子第3位碱基U, C, AA, GU, CUGEvaluation only.
20、Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.二、核糖体是多肽链合成的场所二、核糖体是多肽链合成的场所原核生物真核生物核糖体小亚基大亚基核糖体小亚基大亚基S70S30S50S80S40S60SrRNA16S-rRNA5S-
21、rRNA23S-rRNA18S-rRNA28S-rRNA5S-rRNA5.8S-rRNA蛋白质rpS 21种rpL 36种rpS 33种rpL 49种 不同细胞核糖体的组成不同细胞核糖体的组成 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright
22、2004-2011 Aspose Pty Ltd.核糖体的组成Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.原核生物翻译过程中核蛋白体结构模式原核生物翻译过程中核蛋白体结构模式:A位：氨基酰
23、位位：氨基酰位(aminoacyl site)P位：肽酰位位：肽酰位(peptidyl site)E位：排出位位：排出位(exit site)Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.三
24、、氨基酸转运工具三、氨基酸转运工具tRNA反密码环反密码环氨基酸臂氨基酸臂Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.tRNA的三级结构示意图Evaluation only.Created
25、 with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（一）氨基酰（一）氨基酰-tRNA合成酶合成酶(aminoacyl-tRNA synthetase)氨基酸氨基酸 + tRNA氨基酰氨基酰- tRNAATP AMPPPi氨基酰氨基酰-tRN
26、A合成酶合成酶Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.第一步反应第一步反应氨基酸氨基酸 ATP-E 氨基酰氨基酰-AMP-E AMP PPi Evaluation only.Creat
27、ed with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.第二步反应第二步反应氨基酰氨基酰-AMP-E tRNA 氨基酰氨基酰-tRNA AMP EEvaluation only.Created with Aspose.Slides for .
28、NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd. tRNA搬运功能的搬运功能的忠忠实性性是通是通过以下以下 两条途径两条途径实现的：的： tRNA的的反密反密码子子识别mRNA的的密密码子子。 不同的不同的tRNA有不同的碱基有不同的碱基组成，并由成，并由 不同的不同的氨基氨基酰tRNA
29、合成合成酶识别。既能既能识别特异特异的的tRNA， 又能又能识别特异特异的的氨基酸氨基酸。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（二）起始肽链合成的氨基酰（二）起始肽链合成的氨基酰-
30、tRNA真核生物真核生物： Met-tRNAiMet原核生物原核生物： fMet-tRNAifMetEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.蛋白质生物合成过程蛋白质生物合成过程第二节第
31、二节Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.n翻译的起始(initiation)n翻译的延长(elongation)n翻译的终止(termination )整个翻译过程可分为整个翻译过
32、程可分为 ：翻翻译译过过程程从从阅阅读读框框架架的的5-AUG开开始始，按按mRNA模模板板三三联联体体密密码码的的顺顺序序延延长长肽肽链链，直直至终止密码出现。至终止密码出现。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-20
33、11 Aspose Pty Ltd.一、一、原核生物的翻译过程原核生物的翻译过程（一）（一） 起始阶段起始阶段1.核蛋白体大小核蛋白体大小亚基分离；亚基分离；2.mRNA与小亚与小亚基结合；基结合；3.起始氨基酰起始氨基酰-tRNA与小亚基与小亚基结合；结合； 4.核蛋白体大亚核蛋白体大亚基结合；基结合；30S50SmRNA50S+30S解聚解聚 IF-1IF-3fMetIF-2， GTPAUGfMet50SIF-3GDP+PiIF-1IF-2fMetAUG起始复合物起始复合物Evaluation only.Created with Aspose.Slides for .NET 3.5 Cli
34、ent Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.原核、真核生物各种起始因子的生物功能原核、真核生物各种起始因子的生物功能 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-
35、2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.IF-3IF-11. 核蛋白体大小亚基分离核蛋白体大小亚基分离Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Creat
36、ed with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.A U G53IF-3IF-12. mRNA与小亚基结合与小亚基结合Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Cli
37、ent Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.S-D序列序列 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.IF-3IF-1I
38、F-2GTP3. 起始氨基酰起始氨基酰tRNA( fMet-tRNAimet )与小亚与小亚基结合基结合A U G53Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.IF-3IF-1IF-2G
39、TPGDPPi4. 核蛋白体大亚基结合，起始复合物形成核蛋白体大亚基结合，起始复合物形成A U G53Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（二）（二） 延长阶段延长阶段 肽链延长在
40、核蛋白体上连续性循环式肽链延长在核蛋白体上连续性循环式进行，又称为核蛋白体循环，每次循环增进行，又称为核蛋白体循环，每次循环增加一个氨基酸，包括以下三步：加一个氨基酸，包括以下三步：1.进位进位(entrance)2.成肽成肽(peptide bond formation)3.转位转位(translocation)Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with
41、 Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.n延伸过程所需蛋白因子称为延长因子(elongation factor, EF)原核生物：原核生物：EF-T (EF-Tu, EF-Ts)EF-T (EF-Tu, EF-Ts)EF-GEF-G真核生物：真核生物：EF-1 EF-1 、EF-2 EF-2 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyrigh
42、t 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.原核延长因子生物功能对应真核延长因子EF-Tu促进氨基酰-tRNA进入A位，结合分解GTPEF-1-EF-Ts调节亚基EF-1-EFG有转位酶活性，促进mRNA-肽酰-tRNA由A位前移到P位，促进卸载tRNA释放EF-2肽链合成的延长因子肽链合成的延长因子 Evaluation only.Created with
43、Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.又称注册又称注册(registration)1.进位进位指根据指根据mRNA下下一组遗传密码指导，一组遗传密码指导，使相应氨基酰使相应氨基酰-tRNA进入核蛋白体进入核蛋白体A位。位。 Evaluati
44、on only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.C
45、opyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Tu TsGTPGDPA U G53TuTsGTPEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation on
46、ly.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.2.成肽成肽是由转肽酶是由转肽酶(transpeptidase)催化的肽催化的肽键形成过程。键形成过程。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspo
47、se.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.3.转位转位延长因子EF-G有转位酶( translocase )活性，可结合并水解1分子GTP，促进核蛋白体向mRNA的3侧移动 。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Sl
48、ides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.进进位位转转位位成肽成肽Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011
49、 Aspose Pty Ltd.（三）终止阶段（三）终止阶段 终止相关的蛋白因子称为释放因子终止相关的蛋白因子称为释放因子 (release factor, RF) 原核生物释放因子：原核生物释放因子： RF-1，RF-2，RF-3 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profil
50、e 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.识识别别终终止止密密码码，如如RF-1特特异异识识别别UAA、UAG；而；而RF-2可识别可识别UAA、UGA。诱诱导导转转肽肽酶酶改改变变为为酯酯酶酶活活性性，使使肽肽链链从从核蛋白体上释放。核蛋白体上释放。 释放因子的功能释放因子的功能Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Creat
51、ed with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.原原核核肽肽链链合合成成终终止止过过程程 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5
52、.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.多聚核蛋白体多聚核蛋白体(polysome)Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.二、真二、真核生
53、物的翻译过程核生物的翻译过程（一）（一） 起始阶段起始阶段1.核蛋白体大小亚基分离；核蛋白体大小亚基分离；2.起始氨酰起始氨酰-tRNA(Met-tRNA)与小亚基结合与小亚基结合3.mRNA在核蛋白体小亚基就位；在核蛋白体小亚基就位；4.核蛋白体大亚基结合；核蛋白体大亚基结合；Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for
54、 .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.* 真核生物真核生物与与原核生物原核生物核糖体循核糖体循环的的 起始起始过程程的不同点：的不同点：. 1. 起始起始Met-tRNAMet不需甲不需甲酰化；化；. 2. 起始因子起始因子不少于不少于10种；种；. 3. 小小亚基基先与先与Met-tRNAMet结合，再与合，再与 mRNA结合；合；. 4. ATP供能。供能。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profil
55、e 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（二）（二） 延长阶段延长阶段 延长因子为延长因子为EF-1、EF-2。（三）终止阶段（三）终止阶段 仅需一种释放因子，有仅需一种释放因子，有GTP酶活性。酶活性。Evaluation only.Created with Aspose.Slides for .NET 3.5 Cli
56、ent Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.蛋白质合成后加工和输送蛋白质合成后加工和输送第三节第三节Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspo
57、se Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.主要包括主要包括n多肽链折叠为天然的三维结构多肽链折叠为天然的三维结构 n肽链一级结构的修饰肽链一级结构的修饰n高级结构修饰高级结构修饰 n靶向输送靶向输送Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-201
58、1 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.一、多肽链折叠为天然构象的蛋白质一、多肽链折叠为天然构象的蛋白质（一）分子伴侣（一）分子伴侣 (molecular chaperon) 分子伴侣是细胞一类保守蛋白质，可识分子伴侣是细胞一类保守蛋白质，可识别肽链的非天然构象，促进各功能域和整别肽链的非天然构象，促进各功能域和整体蛋白质的正确折叠。体蛋白质的正确折叠。 1.热休克蛋白热休克
59、蛋白(heat shock protein, HSP) HSP70、HSP40和和GreE族族 2.伴侣素伴侣素(chaperonins) GroEL和和GroES家族家族Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 A
60、spose Pty Ltd.热休克蛋白促进蛋白质折叠的基本作用热休克蛋白促进蛋白质折叠的基本作用结合保护待折叠多肽片段，再释放该片段进结合保护待折叠多肽片段，再释放该片段进行折叠。形成行折叠。形成HSP70和多肽片段依次结合、解离和多肽片段依次结合、解离的循环。的循环。 HSP40结合待结合待折叠多肽片段折叠多肽片段 HSP70-ATP复合物复合物 HSP40- HSP70-ADP-多肽复合物多肽复合物 ATP水解水解GrpE ATPADP复合物解离，释出多肽链片段进行正确折叠复合物解离，释出多肽链片段进行正确折叠 Evaluation only.Created with Aspose.Sli
61、des for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.伴侣素伴侣素GroEL/GroES系统促进蛋白质折叠过程系统促进蛋白质折叠过程 伴侣素的主要作用伴侣素的主要作用为非自发性折叠蛋白质提供能折叠形成天然为非自发性折叠蛋白质提供能折叠形成天然空间构象的微环境空间构象的微环境。
62、 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.（二）蛋白二硫键异构酶（二）蛋白二硫键异构酶 (protein disulfide isomerase, PDI) 在内质网腔活性很高，可在较
63、大区段肽在内质网腔活性很高，可在较大区段肽链中催化错配二硫键断裂并形成正确二硫链中催化错配二硫键断裂并形成正确二硫键连接，最终使蛋白质形成热力学最稳定键连接，最终使蛋白质形成热力学最稳定的天然构象。的天然构象。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Co
64、pyright 2004-2011 Aspose Pty Ltd.（三）肽（三）肽-脯氨酰顺反异构酶脯氨酰顺反异构酶 (peptide prolyl cis-trans isomerase, PPI) 肽酰肽酰-脯氨酰顺反异构酶是蛋白质三维脯氨酰顺反异构酶是蛋白质三维构象形成的限速酶，在肽链合成需形成顺构象形成的限速酶，在肽链合成需形成顺式构型时，可使多肽在各脯氨酸弯折处形式构型时，可使多肽在各脯氨酸弯折处形成准确折叠。成准确折叠。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Cop
65、yright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.二、一级结构修饰二、一级结构修饰（一）肽链（一）肽链N端的修饰端的修饰（二）个别氨基酸的修饰（二）个别氨基酸的修饰（三）多肽链的水解修饰（三）多肽链的水解修饰Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.
66、0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd. 多多肽链中中个个别氨基酸氨基酸的修的修饰o 磷酸化：磷酸化：丝氨酸，氨酸，苏氨酸，酪氨酸氨酸，酪氨酸o 羟基化：基化：脯氨酸，脯氨酸，赖氨酸氨酸o 酰基化：基化：组氨酸氨酸o 甲基化：甲基化：色氨酸色氨酸o 核糖基化：核糖基化：精氨酸精氨酸意意义：或者是蛋白或者是蛋白 质所固有的，或者所固有
67、的，或者 在在调节蛋白蛋白质功能功能 时起重要作用。起重要作用。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.鸦片促黑皮质素原(POMC)的水解修饰NC信号肽信号肽PMOCKRKR103肽肽
68、 ( ？)ACTH -LT -MSH -MSHEndophinEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.三、高级结构修饰三、高级结构修饰（一）亚基聚合（一）亚基聚合 （二）辅基连接（二）
69、辅基连接（三）疏水脂链的共价连接（三）疏水脂链的共价连接 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.四、蛋白质合成后的靶向输送四、蛋白质合成后的靶向输送蛋白质的靶向输送蛋白质的靶向输送(
70、protein targeting) 蛋白质合成后需要经过复杂机制，定向输送蛋白质合成后需要经过复杂机制，定向输送到最终发挥生物功能的细胞靶部位，这一到最终发挥生物功能的细胞靶部位，这一过程称为蛋白质的靶向输送。过程称为蛋白质的靶向输送。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Pro
71、file 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.所所有有靶靶向向输输送送的的蛋蛋白白质质结结构构中中存存在在分分选选信信号号，主主要要为为N末末端端特特异异氨氨基基酸酸序序列列，可可引引导导蛋蛋白白质质转转移移到到细细胞胞的的适适当当靶靶部部位位，这这一一序序列列称称为为信信号号序序列列 。 信号序列信号序列(signal sequence)Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspos
72、e Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.靶向输送蛋白信号序列或成分分泌蛋白信号肽内质网腔蛋白信号肽，C端-Lys-Asp-Glu-Leu-COO-(KDEL序列)线粒体蛋白N端靶向序列（2035氨基酸残基）核蛋白核定位序列（-Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val-，SV40 T抗原）过氧化体蛋白-Ser-Lys-Leu-（PST序列）溶酶体蛋白Man-6-P（甘露
73、糖-6-磷酸）靶向输送蛋白的信号序列或成分靶向输送蛋白的信号序列或成分 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd. 分泌蛋白的靶向输送分泌蛋白的靶向输送 真核细胞分泌蛋白等前体合成后靶向
74、输送过真核细胞分泌蛋白等前体合成后靶向输送过程首先要进入内质网。程首先要进入内质网。 信号肽信号肽(signal peptide) 各种新生分泌蛋白的各种新生分泌蛋白的N端有保守的氨基酸序端有保守的氨基酸序列称信号肽。列称信号肽。 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile
75、 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.信号肽的一级结构信号肽的一级结构Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.信号肽引导真核分泌蛋白进入内质网信号肽引导真核分泌蛋白进入内质网 Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.
