细胞生物学：Chapter 7 线粒体和过氧化物酶体1

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1、CHAPTER 7 Mitochondria and Peroxisome线粒体和过氧化物酶体线粒体和过氧化物酶体The research of mitochondrial functionEarly in 1850,Klliker:osmotic phenomenon.In 1900，Michaelis,Janus green B(詹纳斯绿詹纳斯绿),liver cells:oxygen:Indicator blueIn 1913，Warburg separated mitochondria from cell homogenate(细胞匀浆细胞匀浆)and discovered that

2、it could consume o2.Early in 1940s，Claude invented the isolation technique,obtained mitochondria using salt extraction techniques.In 1948,George Hogeboom,Walter Schneider and George Palade obtained activated mitochondria using sugar extraction techniques.Kenedy and Lehninger:tricarboxylic acid cycle

3、（三羧酸循环），（三羧酸循环），electron-transport，oxidative phosphorylation（氧化磷酸化）（氧化磷酸化）.OUTLINE Mitochondria structure Mitochondria protein localization Mitochondria function-oxidative phosphorylation Mitochondria proliferation Peroxisomes1.Structure of Mitochondria(1)Shape:Granular(粒状粒状),bacilliform(杆状杆状)or elo

4、ngated cylinders with a diameter of 0.51.0m.(2)The number and distributionNumber:obvious difference in different types of cells:1000-2000 Mi in liver cells and no Mi in mammal mature red blood cells.Distribution:the regions requiring energy:fat droplet and sperm tail.鞭毛轴丝鞭毛轴丝肌原纤维肌原纤维线线粒粒体体组组分分的的分分离离

5、芦布若尔：膜蛋白的增溶剂，非离子型表面活性剂 洋地黄皂甘(3)Ultrastructure of Mitochondria Outer membrane Inner membraneIntermembrane space MatrixOuter membrane Lipid/protein:1:1-rich porins（孔蛋白）（孔蛋白）forming large water-filled channels:like a sieve:permeable to all hydrophilic molecules of less than 5 k Da.Outer bacterial membr

6、ane（Gram-negative）TOM complexes（外膜转运蛋白复合体）（外膜转运蛋白复合体）and some special enzymes.Marker enzyme-Monoamine oxidase(单胺氧化酶单胺氧化酶):catalyzing oxidative deaminization(氧化氧化脱氨脱氨)of monoamine(单胺单胺).Inner membrane usually highly convoluted-f o r m i n g a s e r i e s o f infoldings(cristae,嵴嵴 projecting into the

7、matrix and covered with many granum(基粒基粒).Lipid/protein:0.3/1-h i g h p r o p o r t i o n o f cardiolipin(心磷脂心磷脂):the membrane impermeable to ions.双磷脂酰甘油many types of proteins for energy conversion:electron-transport chain,ATP synthase.Marker enzyme-cytochrome oxidase(细胞色素氧化细胞色素氧化酶酶)Many Many types

8、of types of transport proteins:metabolites transport proteins:metabolites into and out of the matrixinto and out of the matrix，TIM complexes TIM complexes（内膜转运（内膜转运蛋白复合体）蛋白复合体）Intermenbrane spacemany soluble enzymes,substrates and cofactors-set up electrochemical gradient.Marker enzyme-adenylatekina

9、se(腺苷酸激酶腺苷酸激酶):Formation of ADP AMP+ATP2ADP Matrix a highly concentrated mixture of hundreds of enzymes-the oxidation of pyruvate,fatty acids and amino acids.Marker enzyme-malate dehydrogenase(苹果酸脱氢苹果酸脱氢酶酶):苹果酸苹果酸 草酰乙酸草酰乙酸.mitochondrial genome,ribosomes,tRNAs and various enzymes for gene expression

10、部位酶的名称部 位酶 的 名 称外膜单胺氧化酶NADH-细胞色素c还原酶（对鱼藤酮不敏感）犬尿酸羟化酶酰基辅酶A合成酶膜间隙腺苷酸激酶二磷酸激酶核苷酸激酶内膜细胞色素b，c，c1，a，a3氧化酶ATP合成酶系琥珀酸脱氢酶-羟丁酸和-羟丙酸脱氢酶肉毒碱酰基转移酶丙酮酸氧化酶NADH脱氢酶（对鱼藤酮敏感）基质柠檬酸合成酶、苹果酸脱氢酶延胡索酸酶、异柠檬酸脱氢酶顺乌头酸酶、谷氨酸脱氢酶脂肪酸氧化酶系、天冬氨酸转氨酶、蛋白质和核酸合成酶系、丙酮酸脱氢酶复合物2.Mitochondria protein targetingCell address target(地址签地址签)1)Translocatio

11、n Mi protein address target(1)The characteristics of leading peptide(导肽或引导肽导肽或引导肽)Sequence characteristics-at the N-terminus-a stretch of about 20-80 amino acid sequence-rich alkaline amino acids(Arginine and lysine)-few acidic amino acids-positively charged amino acids alternate with hydrophobic on

12、es in signal sequences 实验设计实验设计分离线粒体分离线粒体与具有线粒体基质定与具有线粒体基质定位信号的前体蛋白温育位信号的前体蛋白温育胰胰蛋白酶处理蛋白酶处理前导肽如何前导肽如何引导蛋白质引导蛋白质进入线粒体进入线粒体?an amphiphilic a helix(hydrophobic and hydrophilic):specific receptor recognizes this configuration rather than the precise amino acid sequence.subunit of cytochrome oxidase In t

13、he leading peptide,different sequences contain different information.The leading peptide has no specific claim on the guided proteins.Precursor proteins unfolded Many types of translocators involved in the process:(2)Translocation of mitochondrial proteinsTranslocase of the outer and inner membranes

14、The mitochondrial matrix protein translocationThe inner mitochondrial membrane protein translocationOXA负责将基质中线粒体负责将基质中线粒体DNA编码的内膜蛋白编码的内膜蛋白和被运进基质的内膜蛋白插到内膜上和被运进基质的内膜蛋白插到内膜上two Routes A family of metabolite-specific transporters for ATP,ADP,and phosphate,which are multipass transmembrane proteins.The T

15、IM22 complex mediates the insertion of these types of proteins.The intermembrane space protein translocation(a)conservative sortingThe outer membrane protein translocation The proteins translocation to the outer membrane have no leading peptide and their N-terminal amino acids can recognize receptor

16、 in the outer membrane.transiently bind specialized chaperone proteinsboth inserts proteins into the outer membrane and helps them fold properly.First into the intermembrane space across the TOM complex(3)The requisite factor for translocation of Mi proteins leading peptide（导肽）（导肽）chaperone proteins(分子伴侣分子伴侣)receptor（受体）the contact point（接触点）between the outer membrane and inner membrane energy(ATP and Membrane Potential)transit peptidase(转运肽酶转运肽酶)translocators（膜转运复合体）（膜转运复合体）