PHOSPHOLIPASE A2 ACTIVITY TOWARDS PHOSPHATIDYLCHOLINE IN MIXED MICELLES - SURFACE DILUTION KINETICS AND EFFECT OF THERMOTROPIC PHASE-TRANSITIONS
PHOSPHOLIPASE A2 ACTIVITY TOWARDS PHOSPHATIDYLCHOLINE IN MIXED MICELLES - SURFACE DILUTION KINETICS AND EFFECT OF THERMOTROPIC PHASE-TRANSITIONS
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DOI：
10.1016/0003-9861(73)90540-7
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发表时间：
1973-01-01
影响因子：
3.9
通讯作者：
DENNIS, EA
中科院分区：
文献类型：
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作者：
DENNIS, EA
当磷脂与Triton X-100的摩尔比为2:1或更高时，磷脂酶a2将作用于作为底物的双棕榈酰磷脂酰胆碱。据报道，在Triton X-100与磷脂的高摩尔比下的动力学研究表明，磷脂酶a2与底物的结合取决于Triton X-100和磷脂的总浓度，但酶催化速率与Triton X-100浓度成比例地降低。这些结果是根据涉及表面稀释动力学的模型来解释的。讨论了该模型与竞争抑制模型的关系。此外，还报道了磷脂酶a2在不同温度下对双棕榈酰磷脂酰胆碱和二肉豆醇酰磷脂酰胆碱的活性，结果表明双棕榈酰磷脂酰胆碱的热致相变对酶活性有直接影响。
Phospholipase A2will act on dipalmitoyl phosphatidylcholine as substrate when the phospholipid is part of a mixed micelle with Triton X-100 at a molar ratio of Triton to phospholipid of 2:1 or greater. Kinetic studies at high molar ratios of Triton X-100 to phospholipid are reported and show that the binding of phospholipase A2to substrate depends on the total concentration of Triton X-100 and phospholipid, but that the rate of enzymatic catalysis decreases proportionally to the Triton X-100 concentration. These results are interpreted in terms of a model involving surface dilution kinetics. The relationship of this model to that of competitive inhibition is discussed. In addition, the activity of phospholipase A2towards dipalmitoyl phosphatidylcholine and dimyristoyl phosphatidylcholine at different temperatures is reported, and the results show a direct effect of the thermotropic phase transition of dipalmitoyl phosphatidylcholine on enzymatic activity.