CHEMISTRY AND BIOCHEMISTRY OF ENERGY TRANSFER

能量转移的化学和生物化学

• 批准号: 3270187
• 负责人: WILLIAM P JENCKS
• 金额: $ 17.46万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-12-01 至 1988-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3270187
• 关键词: acetaldehyde; adenosine triphosphate; adenosinetriphosphatase; calcium; chemical elimination; chemical reaction; chemical substitution; electron transport; enzyme structure; enzyme substrate; enzyme substrate complex; hydrogen bond; intermolecular interaction; phenylcarboxylate; phosphates; potassium; sodium; spectrometry; thermodynamics

The calcium-transporting ATPase will be examined with the following goals. (A) Determine the nature of the change in catalytic specificity toward phosphate compounds of two forms of the enzyme that normally react with ATP and phosphate, by examination of alternate substrates and phosphate acceptoprs. (B) Determine if potassium ion is occluded during one or more of the steps of the catalytic cycle. (C) Complete the thermodynamic cycle for the enzyme by measuring the equilibrium constant for binding of calcium to enzyme-phosphate. (D) Examine the nature of the slow dissociation of ATP from enzyme-calcium. Succinyl-CoA:acetoacetate coenzyme A transferase will be examined using portions of the coenzyme A molecule separately and together to characterize the rate acceleration of 10 to the 12 brought about by noncovalent interactions with coenzyme A. The strength of hydrogen bonds between small molecules in aqueous solution will be examined using a spectrophotometric technique, and dipole-diplole interactions in water will be characterized by measuring equilibrium constants for addition of substituted alcohols to substituted benzene derivatives. The reported change in mechanism from monomolecular to bimolecular for reactions of benzoyl chlorides will be examined with different nucleophiles to characterize the change in reaction mechanism. General acid catalysis of the addition of water and alcohols to acetaldehyde will be examined to determine if the mechanism involves concerted catalysis. Reactions of substituted methoxymethyl derivatives with nucleophiles will be examined in an attempt to cross the "borderline" between concerted and stepwise reaction mechanisms. The lifetimes of carbanion intermediates will be estimated using diffusion-controlled trapping reactions, and the lifetimes will be related to the mechanisms of elimination mechanisms. Structure-reactivity correlations will be carried out on reactions of substituted phosphates to determine if these reactions proceed through a concerted reaction mechanism rather than a metaphosphate intermediate.

钙传输ATPase将以以下目标进行检查。 （a）确定催化特异性变化的性质 通常与ATP反应的两种酶的磷酸盐化合物 和磷酸盐，通过检查替代底物和磷酸盐 接受者。 （b）确定在一个或多个期间是否会堵塞钾离子 催化循环的步骤。 （c）完成热力学周期 通过测量钙结合的平衡常数，用于酶 磷酸酶。 （d）检查缓慢解离的性质 来自酶 - 钙的ATP。 琥珀酰辅酶A：乙酸辅酶A转移酶 将分别使用辅酶A分子的一部分进行检查，然后 共同表征10到12的速率加速度 关于与辅酶A的非共价相互作用。 将检查水溶液中小分子之间的氢键 使用分光光度计技术和偶极 - 二极管相互作用 水的特征是测量平衡常数 取代的醇用于取代的苯衍生物。 报告 机制从单分子到双分子的机制变化 将使用不同的亲核试剂检查苯甲酰氯化物 表征反应机制的变化。 一般的酸催化 将在乙醛中添加水和醇 确定该机制是否涉及协同催化。 反应 将在 试图跨越协调和逐步之间的“边界” 反应机制。 Carbanion中间体的一生将是 使用扩散控制的捕获反应估计，寿命 将与消除机制的机制有关。 结构反应性相关性将在反应上进行 取代的磷酸盐以确定这些反应是否通过 一致的反应机制，而不是大磷酸盐中间体。