中南大学生物化学考研蛋白质二级三级和四级结构ch6Proteins06.pptx
《中南大学生物化学考研蛋白质二级三级和四级结构ch6Proteins06.pptx》由会员分享,可在线阅读,更多相关《中南大学生物化学考研蛋白质二级三级和四级结构ch6Proteins06.pptx(54页珍藏版)》请在咨信网上搜索。
1、Ch 6 Proteins:secondary,tertiary,and quaternary structure蛋白质的二级、三级和四级结构蛋白质的二级、三级和四级结构For Specialty of Bioengineering and Biotechnology at CSUMr.Jinlan XIAOverview on the Levels of Protein Structures蛋白质结构级别纵览蛋白质结构级别纵览n1st:nAA sequence(possibly with S-S-)氨基酸序列(可能含双硫键)n2nd:nBasic types:a-helix,b-sheetn
2、Less frequently:b-turn 转角,b-bulge凸起nSuper 2nd超二级结构:aa,bb,babn3rd:n3D shape of a folding polypeptide chain 单条折叠肽链的三维结构(形状)n4th:n3D organization of subunits 多亚基三维结构(组构)Key partContent 内容内容nForces influencing protein structure 影响蛋白质结构的作用力nSecondary structure in proteins 蛋白质的二级结构nProtein folding and ter
3、tiary structure 蛋白质折叠和三级结构nSubunit interactions and quaternary structure 亚基相互作用和四级结构Forces influencing protein structure影响蛋白质结构的作用力nHydrogen bond 氢键(合力)nHydrophobic interaction 疏水作用nElectrostatic bond(静)电键或离子键(合力)nVan der Waals force 范德华力nDisulfide bond 双硫键(合力)The forces for each structural level of
4、 proteins 蛋白质每级结构对应的作用力蛋白质每级结构对应的作用力nBasic forces for the 1st level nDisulfide bond 双硫键(合力)nBasic forces for the 2nd levelnHydrogen bond 氢键(合力)nBasic forces for the 3rd level and 4th levelnHydrogen bond 氢键(合力);Hydrophobic interaction 疏水作用;Electrostatic bond(静)电键或离子键(合力);Van der Waals force 范德华力;Disu
5、lfide bond 双硫键(合力)nDifferences in forces between 3rd level and 4th level nThe 4th level of protein is compacted from the 3rd levels of subunits mainly by hydrophobic interaction and Van der Waals force 四级蛋白质结构主要依靠疏水作用力和范德华力将三级结构的亚基紧密堆积而成Secondary structure in proteins 蛋白质的二级结构蛋白质的二级结构nCharacteristic
6、s of the Secondary structure in proteins 蛋白质二级结构的特点nClasses of Secondary Structures 二级结构的类型nSuper secondary Structures 超二级结构超二级结构Characteristics of the Secondary structure in proteins 蛋白质二级结构的特点蛋白质二级结构的特点nThe basic force for 2nd structures is hydrogen bond 二级结构的基本作用力是氢键二级结构的基本作用力是氢键nThe basic types
7、of secondary structures are aa-helix and bb-pleated sheet 二级结构的基本二级结构的基本类型为类型为aa-螺旋和螺旋和b b-折叠片折叠片nSecondary structures are related to the orientations of the amide plane 二级结构与(肽二级结构与(肽键)酰胺平面的取向有关键)酰胺平面的取向有关Secondary structures are related to the orientations of the amide plane 二级结构与(肽键)酰胺平面的取向有关二级结构
8、与(肽键)酰胺平面的取向有关nPeptide units are planar and rigid,but they can rotate with rotation of Ca-N and Ca-C bonds(肽单元是刚性平面,但它们可随着Ca-N 和 Ca-C 键旋转而转动)nRotate angles for Ca-N and Ca-C are and,respectively.(Ca-N 和 Ca-C 旋转角分别为 和)nTypcially,Rotation forbidden for 旋转禁止的典型情况:n(,)=(0,180),two carbonyl oxygens are t
9、oo close;n(,)=(180,0),two amide groups are overlapping;n(,)=(0,0),carbonyl oxygen overlaps with amide group;nTypical ranges of(f,wf,w)for aa-helix and bb-sheet (a-螺旋和b-折叠片的典型旋转角范围):na-helix:(f,w)(-30 -120,0 -90)nb-sheet:(f,w)(-90 -180,90 180)Peptide units are planar and rigid,but they can rotate wit
10、h rotation of Ca a-N and Caa-C bonds 肽单元是刚性平面,但它们可随着肽单元是刚性平面,但它们可随着Ca a-N 和和 Caa-C 键键旋转而转动旋转而转动Rotation of Amide Planes 酰胺平面的旋转酰胺平面的旋转nIf(,)are known for all residues,the structure for the entire backbone is known.nSome(,)are more likely than others in a folded proteinnPositive(,)values correspond t
11、o clockwise rotation around bonds when viewed from the Ca.Zerois defined when the C=O or N-H bond bisects the R-Ca-H angle.:phi,:psiRotation of Amide Planes 酰胺平面的旋转酰胺平面的旋转Peptide bondPeptide bond=180,=180Amide plane酰胺平面a-carbonThe typcial cases of rotation forbidden 旋转禁旋转禁止的典型情况止的典型情况=0,=180two carb
12、onyl oxygens are too close;=0,=0carbonyl oxygen overlaps with amide group=180,=0two amide groups are overlappingRamachandran Plot(图)Antiparallel b-sheet反平行b-折叠片Parallel b-sheet平行b-折叠片a:a-helix (right-handed+)右手a-螺旋(+)aL:a-helix(left-handed-)左手a-螺旋(-)C:collagen triple helix 胶原三股螺旋p:4.416 helix(closed
13、 ring)4.416螺旋(闭合环)n:Number of AA residues/turn of helix 氨基酸残基数/螺旋圈:60:45-50Classes of Secondary Structures of Proteins 蛋白质的蛋白质的二二级结构类型级结构类型na-Helix (a-螺旋)n3.613 helix(normal)n310,4.416(not often)nb-(pleated)sheet (b-折叠片)nParallel(normally 5 strands)平行b-折叠片(通常5 肽链)nAnti-parallel(=2 strands)反平行b-折叠片(通
14、常=2 肽链)nb-Turn(b-转角)nb-bulge(b-凸起)3.613 helix每个螺旋含3.6个氨基酸残基每个氢键相隔的原子数 The Alpha Helix(a-螺旋)nRight-handed 右手螺旋nH-bond patterns of the alpha helix(a-螺旋的氢键特征)nH-bond(氢键)nC=O(ith AA residue)-H-N(amide proton of the(i+4)th residue)nCommon a-helix(常见的a-螺旋)n3.613 helixnNo Proline except at the beginning of
15、 an a-helix 除非在螺旋起端,否则不含脯氨酸nGlu,Met,Ala,Leu more often occurred 常含有谷氨酸、蛋氨酸、丙氨酸和亮氨酸nLinus Pauling(Nobel Prize in Chemistry,1954)figured out the structure of a-keratin helix Secondary StructuresH-bond(氢键)n C=O(ith AA residue)-H-N(amide proton of the(i+4)th residue)n3.613 helix5.4 (3.6 amino acid resid
16、ues per each turn)1.5 (each amino acid residue)Hypothesized axisa a-helix(2nd)Residues per turn:3.6Rise per residue:1.5 Rise per turn:5.4(,)=(-60,-45)C=O N-H side chainTotal dipole moment Four different graphic representations of the a a-helixRibbon structureSpace-fillinggraphicShowingpeptide planes
17、Paulings modelSecondary Structuresb b-Pleated sheet is formed from b-b-Strands(b b折叠片是由折叠片是由b-b-肽链形成的肽链形成的)Due to the planarity of the peptide bond that forces the formation of the b b-pleated sheet由于肽键的平面性促使形成由于肽键的平面性促使形成b b-折叠片折叠片Side-view of one peptide chainb-b-Strandsb b-Pleated sheetnTwo types
18、 of b-sheets and their H-bond characteristics 两种类型b折叠片和它们的氢键特征:nParallel b-sheet 平行b折叠片nLess extended(0.325 nm between two residues)欠伸展nLarger(at least 5 strands)nAnti-parallel b-sheet 反平行b折叠片nMore extended(0.347 nm between two residues)较伸展nSmaller size(=2 strands)The Beta Turn(b-转角)nBeta turns conn
19、ect beta strands and reverse the direction of beta strands b-转角连接b-肽链,并使b-肽链改变方向nH-bond (氢键(特征)n310:C=O(ith residue)to H-N(amide proton of the(i+3)th residue)nPro,Gly more often occurred(常含脯氨酸和甘氨酸)nTight turn promotes formation of antiparallel beta sheets.(b-转角促使反平行b-片的形成)Two kinds of b b-turn Secon
20、dary StructuresBeta Bulge(b b凸起凸起)nSmall,nonrepetitive(小,不具重复性)nMuch less occurs,and few irregularly in antiparallel b-structures(很少见,有时不规则地出现在反平行b-结构中)Classic bulgeC-1 bulgeWide bulgeLeads to bending of the anti-parallel beta-strandsSecondary StructuresThree basic types of super secondary Structure
21、s 三种基本超二级结构三种基本超二级结构naa nCoiled-coil 铰链式铰链式nHelix bundles 螺旋簇式螺旋簇式nbb nHairpins 发夹式发夹式nbabnCross-overs 交叉式交叉式Super Secondary Structures (I)naaaanCoiled-coil 铰链式nCommon alpha helix structure nHelix bundles 螺旋簇式nRefers to three or more helices packing togetherSuper secondary Structures(II)nbb nHairpin
22、s 发夹式发夹式nConnect two antiparallel strands;nbabnCross-overs 交叉式交叉式nConnect two parallel strandsRight-handed Cross-overTo dive into the tertiary structure formsProtein Folding and Tertiary StructureArchitecture of protein molecules 蛋白分子构造蛋白分子构造Three global classes based on shape and solubility:Fibrous
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 中南 大学 生物化学 考研 蛋白质 二级 三级 结构 ch6Proteins06
1、咨信平台为文档C2C交易模式,即用户上传的文档直接被用户下载,收益归上传人(含作者)所有;本站仅是提供信息存储空间和展示预览,仅对用户上传内容的表现方式做保护处理,对上载内容不做任何修改或编辑。所展示的作品文档包括内容和图片全部来源于网络用户和作者上传投稿,我们不确定上传用户享有完全著作权,根据《信息网络传播权保护条例》,如果侵犯了您的版权、权益或隐私,请联系我们,核实后会尽快下架及时删除,并可随时和客服了解处理情况,尊重保护知识产权我们共同努力。
2、文档的总页数、文档格式和文档大小以系统显示为准(内容中显示的页数不一定正确),网站客服只以系统显示的页数、文件格式、文档大小作为仲裁依据,平台无法对文档的真实性、完整性、权威性、准确性、专业性及其观点立场做任何保证或承诺,下载前须认真查看,确认无误后再购买,务必慎重购买;若有违法违纪将进行移交司法处理,若涉侵权平台将进行基本处罚并下架。
3、本站所有内容均由用户上传,付费前请自行鉴别,如您付费,意味着您已接受本站规则且自行承担风险,本站不进行额外附加服务,虚拟产品一经售出概不退款(未进行购买下载可退充值款),文档一经付费(服务费)、不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
4、如你看到网页展示的文档有www.zixin.com.cn水印,是因预览和防盗链等技术需要对页面进行转换压缩成图而已,我们并不对上传的文档进行任何编辑或修改,文档下载后都不会有水印标识(原文档上传前个别存留的除外),下载后原文更清晰;试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓;PPT和DOC文档可被视为“模板”,允许上传人保留章节、目录结构的情况下删减部份的内容;PDF文档不管是原文档转换或图片扫描而得,本站不作要求视为允许,下载前自行私信或留言给上传者【可****】。
5、本文档所展示的图片、画像、字体、音乐的版权可能需版权方额外授权,请谨慎使用;网站提供的党政主题相关内容(国旗、国徽、党徽--等)目的在于配合国家政策宣传,仅限个人学习分享使用,禁止用于任何广告和商用目的。
6、文档遇到问题,请及时私信或留言给本站上传会员【可****】,需本站解决可联系【 微信客服】、【 QQ客服】,若有其他问题请点击或扫码反馈【 服务填表】;文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“【 版权申诉】”(推荐),意见反馈和侵权处理邮箱:1219186828@qq.com;也可以拔打客服电话:4008-655-100;投诉/维权电话:4009-655-100。