KINETIC-ANALYSIS OF THE MALONYL COENZYME-A DECARBOXYLATION AND THE CONDENSATION REACTION OF FATTY-ACID SYNTHESIS - APPLICATION TO THE STUDY OF MALONYL COENZYME-A INACTIVATED CHICKEN LIVER FATTY-ACID SYNTHETASE
KINETIC-ANALYSIS OF THE MALONYL COENZYME-A DECARBOXYLATION AND THE CONDENSATION REACTION OF FATTY-ACID SYNTHESIS - APPLICATION TO THE STUDY OF MALONYL COENZYME-A INACTIVATED CHICKEN LIVER FATTY-ACID SYNTHETASE
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DOI：
10.1021/bi00515a015
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发表时间：
1981-01-01
期刊：
影响因子：
2.9
通讯作者：
KUMAR, S
中科院分区：
文献类型：
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作者：
SRINIVASAN, KR;KUMAR, S
对丙二酰辅酶A脱羧反应和脂肪酸合成缩合- co2交换反应进行了动力学分析。实验证据支持的分析定义了丙二酰辅酶a脱羧定量反映酶结合酰基和丙二酰基之间缩合反应活性的条件。NADP+通过降低导致三乙酸内酯形成的过程的速率，减少放射性标记的丙二酰辅酶a释放14CO2。为了精确测量，酶的浓度应小于200.mu。g/mL，丙二酰辅酶a /酶比值应小于等于200。反应时间短（1分钟或更短），包含NADP+ (100 .mu)。M)提高测量的准确性。这些分析用于解释丙二酰辅酶a介导的鸡肝脂肪酸合成酶失活的机制，并适用于确定包含二聚体酶的多功能多肽链的功能凝聚位点。
A kinetic analysis of the decarboxylation of malonyl-CoA and the condensation-CO2 exchange reaction of fatty acid synthesis was carried out. The analysis supported by experimental evidence defines conditions under which the decarboxylation of malonyl-CoA quantitatively reflects the activity for the condensation reaction between enzyme-bound acyl and malonyl groups. NADP+ decreases the release of 14CO2 from radiolabeled malonyl-CoA by lowering the rates of the processes leading to the formation of triacetic acid lactone. For accurate measurements the enzyme concentration should be < 200 .mu.g/mL, and malonyl-CoA/enzyme ratios should be 200 or less. Short reaction periods (1 min or less) and inclusion of NADP+ (100 .mu.M) enhance the accuracy of measurements. These analyses were used to explain the mechanism of malonyl-CoA mediated inactivation of chicken liver fatty acid synthetase and are appropriate for determining the functional condensing site of the polyfunctional polypeptide chains comprising the dimeric enzyme.