生物化学第二章酶

1、会计学1生物化学第二章酶生物化学第二章酶酶单成份酶：脲酶、蛋白酶、淀粉酶、核糖核酸酶等。双成份酶酶蛋白辅因子（简单蛋白质）（结合蛋白质）（apoenzyme）（cofacter)辅酶（coenzyme)辅基(prosthetic group)全酶(holoenzyme）= 酶蛋白 + 辅因子CH2OHCH2OHA1A2麦角固醇7-脱氢胆固醇22-双氢麦角固醇7-脱氢谷固醇维生素D2维生素D3维生素D4维生素D5HOROHOR2R1R3OOOOCH2CHC(CH3)CH2CH25CHC(CH3)2Cl-N+SCH3CH2CH2OHNNNH2H3CCH2NNNH2H3CCH2N+SCH3CH2CH

2、2OPOOPOHOHOOHCl-NCCNHNNOOCH2CHCHCHCH2OPOHOHOHOHOOHCH3CH3CH3CH3NCCNHNNOOCH2CHCHCHCH2OPOOHOHOHOOHOCH2OHOHNNNH2NNFMN FADCH2CCH3CH3CHOHCONHCH2CH2COHCOOHOCH2CCH3CH3CHOHCONHCH2CH2CNHCH2CH2SHOOOOHPOOHHONNNH2NNOPOOOHPOOOHCH2NCOOHNCONH2OCH2OPOPOCH2OHOHO OO-O-N+CONH2OOHOH(OPO3H2)NNNH2NNNH3CHOCH2NH2CH2OHNH3CHO

3、CHOCH2OHNH3CHOCHOCH2OPOHOOHNH3CHOCH2NH2CH2OPOHOOH磷酸吡哆醛 磷酸吡哆胺HNNHCOCHH2CS(CH2)4COOHNNH2NOHNNHHCH2HHHNHCONHCHCOOHCH2CH2COOHCCCCCCH2OHOHOHOHHOHOOCCOOOHHOHCH2OHCCCSCHSCHCH2CH2CH2CH2CH2COOHOOCH3OCH3OCH3(CH2CH CCH2)nHCH3n=6-10催化部位(Catalytic site): 酶分子中促使底物发生化学变化的部位称为催化部位。l通常将酶的结合部位和催化部位总称为酶的活性部位或活性中心。l结合部

4、位决定酶的专一性，l催化部位决定酶所催化反应的性质。 调控部位(Regulatory site):酶分子中存在着一些可以与其他分子发生某种程度的结合的部位，从而引起酶分子空间构象的变化，对酶起激活或抑制作用H2NCHCCH2OHOOHOHH2NCHCCH2OHOSHSHH2NCHCCH2OHONNHNNHH2NCHCCH2OHOCH2COHOH2NCHCCH2OHOCOHOCOOHH2NCHCCH2OHOCH2CH2CH2NH2NH2H2NCHCCH2OHOOHOHCH3CHCOOHOHNAD+H+CH3CCOOHONADHCH3CHCOOHNH2HOOCCH2CH2CCOOHOHOOCCH2

5、CH2CHCOOHNH2CH3CCOOHOH2OCOOCH2CH3RRCOOHCH3CH2OHHOOCCH=CHCOOHH2OHOOCCH2CHCOOHOHOCH2OHOHOHOHOHOCH2OHCH2OHOHOHOH33333333335555555555BBBBBPPP+POHPPBBBBPPPPPBP-COOH, -NH3, -SH,+OHNHNH+-COO , -NH2, -S , -.-O-NHN:V=Vmax SKm + SK Km m 米氏常数米氏常数V Vmax max 最大反应速度最大反应速度 1 1 K Km 1 1m 1 1 = = + + V V V Vmax S max S V Vmaxmax-4-202468100.00.20.40.60.81.01/S(1/mmol.L-1)1/v1/Vmax斜率斜率=Km/Vmax-1/Km102030405060708090020406080100Temperature OCRelative Activity (%)最适温度 动力学特点：不符合米曼方程双曲线。V=Vmax SKm + SNH3CHOCH2NH2CH2O