Evolution of Cellular ATP Buffering and Energy Transport Systems

[63 . 1907]艾灵顿活细胞实际上就像内燃机一样工作。各种各样的燃料，如脂肪和碳水化合物，通过代谢燃烧产生水、二氧化碳和一种被称为ATP的化学能货币。ATP为细胞中大多数有用的过程提供能量，包括生物合成、物质跨膜泵送和细胞运动。肌肉和神经细胞表现出高和可变的ATP利用率，往往超过代谢ATP合成的能力。在脊椎动物中，这些细胞储存一种被称为磷酸肌酸的化学物质，在能量消耗旺盛的时期充当能量储存库。磷酸肌酸属于一个能量储存化合物家族，统称为磷酸。在非脊椎动物群体中发现了各种其他的磷（如磷酸精氨酸、磷酸牛磺酸胺）。这些化合物的作用方式类似于磷酸肌酸。然而，某些基本的功能差异是明显的。本研究项目将利用高场核磁共振（NMR）波谱和常规生化方法进一步研究不同磷化合物的功能差异。一旦这些差异被描绘出来，数学模型将被开发来评估这些化合物在各种生物环境下的功能（不同的细胞类型，细胞超微结构，ATP利用率）。由此产生的模拟将用于评估和随后解释各种动物群体中特定磷素的分布。这些研究将提供深入了解细胞能量代谢的进化，这是一个对所有细胞功能至关重要的过程。

9631907 Ellington Living cells, in effect, behave as internal combustion engines. Various fuels such as fats and carbohydrates are metabolically combusted yielding water, carbon dioxide and a form of chemical energy currency known as ATP. ATP provides the energy for most useful processes in the cell including biosynthesis, pumping of materials across membranes and cell movement. Muscle and nerve cells display high and variable rates of ATP utilization which often exceed the capacity for metabolic ATP synthesis. In vertebrates, these cells stockpile a chemical known as creatine phosphate which acts as a reservoir of energy during periods of intense energy use. Creatine phosphate belongs to a family of energy storage compounds collectively known as phosphagens. A variety of other phosphagens (ca., arginine phosphate, taurocyamine phosphate) are found in the non-vertebrate animal groups. These compounds function in a manner analogous to that of creatine phosphate. However, certain fundamental functional differences are evident. The present research project will further investigate functional differences in the diverse phosphagen compounds using high field nuclear magnetic resonance (NMR) spectroscopy and conventional biochemical methods. Once these differences have been delineated, mathematical models will be developed to evaluate the functioning of these compounds in various kinds of biological contexts (different cell types, cell ultrastructure, rates of ATP utilization). The resulting simulations will be used to evaluate and subsequently explain the distribution of particular phosphagens in various animal groups. These studies will provide insight into the evolution of cellular energy metabolism, a process vital to the functioning of all cells.