Trypsin Chymotrypsin Elastase 切Lys,Arg 切Trp,Phe,Tyr 切Aa,Gly C-N-C-C-N- N N -N-C-C-N cIcIcIcN+ CH3 三b Shallow and 8 H non-polar pocket 20 cOO Non-polar pocket
COOC Asp Trypsin Chymotrypsin Elastase 切 Lys, Arg 切 Trp, Phe, Tyr 切 Ala, Gly Non-polar pocket Deep and negatively charged pocket Shallow and non-polar pocket O O –C–N–C–C–N– C C C C NH3 + O O –C–N–C–C–N– C O O –C–N–C–C–N– CH3 Juang RH (2004) BCbasics
Enzyme classification Table 8-3 International classification of enzymes No Class Type of reaction catalyzed Oxidoreductases Transfer of electrons (hydride ions or H atoms Transferases Group-transfer reactions drolase Hydrolysis reactions(transfer of functional groups to water) Lyases Addition of groups to double bonds, or formation of double bonds by removal of groups 5 Isomerases Transfer of groups within molecules to yield isomeric forms 6 Ligases Formation of C-C.C-S C-O. and C-N bonds by condensation reactions coupled to ATP cleavage e Most enzymes catalyze the transfer of electrons, atoms, or functional groups. They are therefore classified, given code numbers, and assigned names according to the type of transfer reaction. the group donor, and the group acceptor
Enzyme classification
2. Enzyme classification (1)氧化还原酶 Oxidoreductase 氧化还原酶催化氧化-还原反应 主要包括脱氢酶( dehydrogenase和氧化酶( Oxidase) 如,乳酸( Lactate)脱氢酶催化乳酸的脱氢反应。 CH3 CHCOOH + NAD-CH3CCOOH+ NADH +H OH
2. Enzyme classification • 氧化-还原酶催化氧化-还原反应。 • 主要包括脱氢酶(dehydrogenase)和氧化酶(Oxidase)。 • 如，乳酸(Lactate)脱氢酶催化乳酸的脱氢反应。 (1) 氧化-还原酶 Oxidoreductase CH3CHCOOH OH NAD + H + CH3CCOOH O NADH
2. Enzyme classification 2展转 transferase 转移酶催化基团转移反应,即将一个底物分子的基团或原子转移到 另一个底物的分子上。 例如,谷丙转氨酶催化的氨基转移反应 CH3CHCOOH + HooCCH CHCCOOH NH2 O CH3CCOOH HOOCCH CH2CHCOOH O NH2
2. Enzyme classification • 转移酶催化基团转移反应，即将一个底物分子的基团或原子转移到 另一个底物的分子上。 例如， 谷丙转氨酶催化的氨基转移反应。 (2) 转移酶 Transferase CH3 CHCOOH NH2 HOOCCH2 CH2 CCOOH O HOOCCH2 CH2 CHCOOH NH2 CH3 CCOOH O
2. Enzyme classification (3)水解酶 hydrolase 水解酶催化底物的加水分解反应。 主要包括淀粉酶、蛋白酶、核酸酶及脂酶等。 例如,脂肪酶 Lipase)催化的脂的水解反应 R-COOCH2 CH3 H2O RCOOH CH3CHOH
2. Enzyme classification • 水解酶催化底物的加水分解反应。 • 主要包括淀粉酶、蛋白酶、核酸酶及脂酶等。 • 例如，脂肪酶(Lipase)催化的脂的水解反应： (3) 水解酶 hydrolase H2O R COOCH2 CH3 RCOOH CH3 CH2OH