CHEMISTRY AND BIOCHEMISTRY OF ENERGY TRANSFER

能量转移的化学和生物化学

• 批准号: 3484364
• 负责人: WILLIAM P JENCKS
• 金额: $ 26.7万
• 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 1993-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3484364
• 关键词: acetaldehyde; adenosine triphosphate; adenosinetriphosphatase; bioenergetics; biological transport; calcium; chemical elimination; chemical reaction; chemical substitution; chemical transfer reaction; electron transport; enzyme mechanism; enzyme structure; enzyme substrate; hydrogen bond; hydrogen transport; laboratory rabbit; phenylcarboxylate; phosphates; potassium; sarcoplasmic reticulum; sodium; spectrometry; thermodynamics; transacylation

Mechanisms of group transfer reactions and their catalysis will be studied in enzymic and nonenzymic systems and mechanisms for the conversion of chemical energy into work will be examined with the calcium-transporting ATPase of sarcoplasmic reticulum. This subject is important in the control and function of healthy and diseased muscle. The role of exact fixation and entropy loss in enzyme catalysis will be probed with partial and complete substrates for Coenzyme A transferase and by examining small changes in the size of substituents that are remote from the reacting groups of substrates. Rate and equilibrium constants for formation and breaking of hydrogen bonds in aqueous solution will be examined. The mechanism of calcium internalization and the internal calcium binding site of the calcium ATPase will be characterized. Phosphoryl transfer will be examined by a search for general base catalysis and for catalysis of the cleavage of phosphorylated pyridines by alkaline phosphatase. Acyl cyanides will be examined as substrates for chymotrypsin in an attempt to estimate the role of proton transfer to the leaving group in catalysis; concerted proton transfer to the leaving cyanide is not possible. The mechanism of proton transfer between electronegative atoms will be examined by determining Bronsted plots and isotope effects for general acid and general base catalysis of ester aminolysis involving diffusion-controlled proton transfer. Reactions of acyl halides will be examined to evaluate the importance of acylium ion intermediates and the possibility of a bimolecular substitution mechanism. The mechanism of proton removal from carbon will be studied using the sulfonium ion as activating group to determine if there are changes in transition state structure with changing reactant structure; these compounds are expected to have a small intrinsic barrier for proton transfer that may make such changes more readily detectible.

基团转移反应的机理及其催化作用 在酶和非酶系统中进行研究， 化学能转化为功的问题将用 肌浆网的钙转运ATP酶。 这 主题是重要的控制和功能的健康和 患病的肌肉 精确固定和熵损失在 酶的催化作用将被部分和完全探测 辅酶A转移酶的底物，并通过检查小 在远离的取代基的大小的变化 反应底物的基团。 速率常数和平衡常数 用于在水溶液中形成和破坏氢键 将被审查。 钙离子的内吞机制和 钙ATP酶的内部钙结合位点将是 表征了 磷酰转移将通过检索 用于一般碱催化和用于催化 通过碱性磷酸酶磷酸化吡啶。 酰腈 将作为胰凝乳蛋白酶的底物进行检查， 估计质子转移到离去基团的作用 催化;协同质子转移到离开氰化物是 不可能 质子转移的机理 电负性原子将通过测定布朗斯台德 一般酸和一般碱的图和同位素效应 涉及扩散控制的酯氨解催化 质子转移 将研究酰卤的反应， 评估酰基鎓离子中间体的重要性， 双分子取代机制的可能性。 的 质子从碳去除的机制将使用 锍离子作为活化基团，以确定是否存在 过渡态结构随反应物的变化 结构;这些化合物预计具有小的内在 质子转移的障碍，可能使这种变化更多 很容易被发现