INTERFACIAL ACTIVATION OF SOLUBLE LIPOLYTIC ENZYMES

这项研究的目标是了解分子力学的 水溶性脂肪分解酶的界面活性。 我们用核磁共振， QLS、SANS和荧光技术结合动力学分析 研究磷脂与非特异性磷脂酶的相互作用 磷脂酰肌醇特异性磷脂酶C（PI-PLC） 蜡状芽孢杆菌。 所考虑的一般性关键问题包括以下内容。 (i)磷脂界面在不同的聚集体结构中是如何变化的， 并且这些变化是否与磷脂酶活性（即， 我们能否解释“界面活化”、“底物抑制”、“表面 稀释”等）？ (ii)什么磷脂酶C？ (iii)能否统一 开发定量说明磷脂酶动力学模型 以单体、胶束、洗涤剂混合胶束的形式对底物的速率，以及 双层囊泡 这些研究的结果将使我们了解复杂的 两种细菌PLC型酶的界面行为。 以来 细菌非特异性PLC具有与至少一种 中性哺乳动物PLC，我们开发的一般现象和原理， B。蜡状酵母的酶可以外推到重要的哺乳动物 内切酶 后者在细胞活化中起关键作用，包括 用于细胞内Ca 2+动员的肌醇磷酸的产生， 甘油二酯的生成，用于激活蛋白激酶C。

The goal of this research is to understand the molecular mechanics of the interfacial activity of water-soluble lipolytic enzymes. We are using NMR, QLS, SANS, and fluorescence techniques in conjunction with kinetic analyses to investigate phospholipid interactions with the nonspecific phospholipase C (PLC) and the phosphatidylinositol-specific phospholipase C(PI-PLC) form Bacillus cereus. General key problems considered include the following. (i) How do phospholipid interfaces vary in different aggregate structures, and can these variations be correlated with phospholipase activity (i.e. can we explain "interfacial activation", "substrate inhibition", "surface dilution", etc.)? (ii) What phospholipase C species? (iii) Can a unified kinetic model be developed that quantitatively accounts for phospholipase rates toward substrate as monomer, micelles, detergent mixed micelles, and bilayer vesicles? The results of these studies will allow us to understand the complex interfacial behavior of two bacterial PLC type enzymes. Since the bacterial nonspecific Plc has characteristics similar to at least on neutral mammalian PLC, the general phenomena and rationale we develop for the B. cereus enzymes may be extrapolated to the important mammalian enzymes. The latter play key roles in cellular activation including the production of inositol phosphates for intracellular Ca2+ mobilization and the generation of diglyceride for activation of protein kinase C.