Molecular mechanisms of lithium action on kinases

锂对激酶作用的分子机制

基本信息

批准号：
10500972
负责人：
PETER S KLEIN
金额：
$ 32.51万
依托单位：
UNIVERSITY OF SOUTH FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-17 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10500972
关键词：
Address Advocate Affect Affinity Base Pairing Benchmarking Binding Binding Proteins Biochemical Bioinformatics Biological Biophysics Bipolar Disorder Blood Catalytic Domain Chemicals Chemistry Cyclic AMP-Dependent Protein Kinases Dementia Development Dose Enzymes Equilibrium Exposure to Foundations Free Energy Future Genes Glycogen Synthase Kinase 3 Goals Growth Human In Vitro Individual Ions Lithium Maps Medical Methods Molecular Mutagenesis Mutation Natural Selections Outcome Pathway interactions Persons Phenotype Phosphoric Monoester Hydrolases Phosphotransferases Physiological Physiological Processes Predisposition Process Protein Kinase Proteins Protocols documentation Quantum Mechanics Reaction Resistance Sampling Signal Pathway Statistical Bias Therapeutic Time Variant Yeasts biophysical techniques design dietary trace element dosage enzyme mechanism enzyme model experimental study glycogen synthase kinase 3 beta improved in vivo insight molecular mechanics mutation screening patient response side effect simulation

项目摘要

Summary/Abstract Lithium is a first-line therapy for millions of people suffering from bipolar disorder, and is promising for inhibiting development of dementia. Experiments show that a primary mode by which Li+ alters physiological processes is by reducing activities of a surprisingly limited number of Mg2+-dependent phosphoryl-transferring enzymes, including phosphomonoesterases and protein kinases. While the (Li-independent) catalytic mechanisms of these enzymes are quite well-understood, much about the mechanistic details underlying their Li-susceptibility remain unknown. Not surprisingly, it remains a major challenge to design enzyme variants that are Li-resistant, and use them to disentangle signaling pathways associated with Li-susceptibilities of individual enzymes. Here we focus on Li+'s action on kinases, and address the following problem central to alleviating the issues raised above. Experiments on 71 human kinases show a wide range of Li-susceptibility — many are unaffected and others are affected to varying degrees. But there is no explanation for these variations. We address this gap in our understanding of Li-action by using state-of-the-art molecular mechanics (MM), quantum mechanics (QM) and QM/MM simulations, as well as mutagenesis experiments guided by bioinformatics and natural selection. Supported by experiments, we explore the overarching hypothesis that Li+ affects kinase activity by interacting directly with their catalytic sites. In Aim 1, simulations will examine how Li+ binds kinases, and how Li+ binding reduces kinase activity. Additionally, simulations will provide insights into potential allosteric effects that regulate catalytic site activity. Our biochemical, cellular and in vivo experiments in Aim2 are designed to (i) systematically examine effects of sequence differences between Li-sensitive and Li- resistant kinases, with the goal of making a Li-sensitive enzyme, GSK-3, resistant to Li+; and (ii) discover key residues that make certain kinases Li-sensitive. Experiments will also validate findings from simulations, and at the same time, simulations will provide molecular insights to interpret results from mutational experiments. Combined analysis of results from simulations and experiments will yield a Li-resistant GSK-3, which is significant because it will, for the first time, enable us to disentangle GSK-3-driven physiological effects of Li+ from those of other Li-sensitive enzymes. This study will also provide a physical basis to explain observed variations of Li-sensitivity across kinases, and these biophysical findings will serve as foundations for future efforts to make other Li-sensitive kinases resistant to Li+, and map their specific phenotypes. We expect that such efforts will improve understanding and predictions of patient responses to Li-treatments and dosages, which remains a difficult task. This will both expedite therapy and avoid exposure to side effects. Finally, this study will explore new advancements in modeling enzyme reactions and yield a validated polarizable force field for describing Li+/Mg2+ interactions with proteins. This will enable future reliable studies of Li-action on proteins not considered in this project and broaden exploration of the full range of Mg-binding proteins.

摘要/摘要锂是数百万双相情感障碍患者的一线疗法，并且有望用于治疗实验表明，Li+ 改变生理的主要模式。过程是通过减少令人惊讶的有限数量的 Mg2+ 依赖性磷酰基转移的活性酶，包括磷酸单酯酶和蛋白激酶，而（不依赖锂）催化。这些酶的机制已被很好地理解，很多关于其背后的机制细节锂敏感性仍然未知，毫不奇怪，设计具有这种特性的酶变体仍然是一个重大挑战。是锂抗性的，并用它们来解开与个体锂敏感性相关的信号通路在这里，我们重点关注 Li+ 对激酶的作用，并解决以下对于缓解酶的影响至关重要的问题。上面提出的问题对 71 种人类激酶进行的实验显示出广泛的锂敏感性——许多激酶都是锂敏感性的。没有受到影响，而其他人则受到不同程度的影响，但对这些变化没有任何解释。我们通过使用最先进的分子力学来解决我们对锂作用理解上的这一差距 (MM)、量子力学 (QM) 和 QM/MM 模拟，以及由在生物信息学和自然选择的支持下，我们探索了 Li+ 的总体假设。在目标 1 中，模拟将检查 Li+ 如何影响激酶活性。此外，模拟还将提供有关 Li+ 结合如何降低激酶活性的见解。调节催化位点活性的潜在变构效应。 Aim2中的目的是（i）系统地检查Li敏感和Li-之间序列差异的影响抗性激酶，目标是使锂敏感酶 GSK-3 对 Li+ 具有抗性；以及 (ii) 发现关键使某些激酶对锂敏感的残基实验还将验证模拟的结果。同时，模拟将提供分子见解来解释突变实验的结果。模拟和实验结果的综合分析将产生抗锂 GSK-3，它是意义重大，因为它将首次使我们能够解开 GSK-3 驱动的 Li+ 的生理效应这项研究也将为解释观察到的现象提供物理基础。不同激酶的锂敏感性的变化，这些生物物理发现将为未来奠定基础使其他锂敏感激酶对 Li+ 具有抗性，并绘制它们的特定表型。这将提高对患者对锂治疗和剂量反应的理解和预测，这仍然是一项艰巨的任务，这既可以加快治疗速度，又可以避免副作用。研究将探索酶反应建模的新进展并产生经过验证的极化力描述 Li+/Mg2+ 与蛋白质相互作用的领域，这将使未来对 Li+ 作用的可靠研究成为可能。本项目中未考虑的蛋白质，并扩大了对全系列镁结合蛋白的探索。