Morris Sidney M
Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
J Nutr. 2007 Jun;137(6 Suppl 2):1602S-1609S. doi: 10.1093/jn/137.6.1602S.
Arginine has multiple metabolic fates and thus is one of the most versatile amino acids. Not only is it metabolically interconvertible with the amino acids proline and glutamate, but it also serves as a precursor for synthesis of protein, nitric oxide, creatine, polyamines, agmatine, and urea. These processes do not all occur within each cell but are differentially expressed according to cell type, age and developmental stage, diet, and state of health or disease. Arginine metabolism also is modulated by activities of various transporters that move arginine and its metabolites across the plasma and mitochondrial membranes. Moreover, several key enzymes in arginine metabolism are expressed as multiple isozymes whose expression can change rapidly and dramatically in response to a variety of different stimuli in health and disease. As illustrated by the questions raised in this article, we currently have an imperfect and incomplete picture of arginine metabolism for any mammalian species. It has become clear that a more complete understanding of arginine metabolism will require integration of information obtained from multiple approaches, including genomics, proteomics, and metabolomics.
精氨酸有多种代谢途径，因此是最具多功能性的氨基酸之一。它不仅在代谢上可与脯氨酸和谷氨酸相互转化，还可作为合成蛋白质、一氧化氮、肌酸、多胺、胍丁胺和尿素的前体。这些过程并非在每个细胞内都全部发生，而是根据细胞类型、年龄和发育阶段、饮食以及健康或疾病状态而差异表达。精氨酸代谢还受到各种转运蛋白活性的调节，这些转运蛋白可将精氨酸及其代谢产物转运穿过质膜和线粒体膜。此外，精氨酸代谢中的几种关键酶以多种同工酶的形式表达，其表达可在健康和疾病状态下对各种不同刺激做出快速而显著的变化。正如本文所提出的问题所示，目前我们对任何哺乳动物物种的精氨酸代谢情况的了解都不完美且不完整。显然，要更全面地了解精氨酸代谢，需要整合从多种方法（包括基因组学、蛋白质组学和代谢组学）获得的信息。
