Kelley W N, Holmes E W, Van der Weyden M B
Arthritis Rheum. 1975 Nov-Dec;18(6 Suppl):673-80. doi: 10.1002/art.1780180706.
In the present discussion we have presented our views on how purine biosynthesis de novo is regulated in man. The rate of the initital step unique to purine ribonucleotide biosynthesis de novo is controlled by the intracellular concentration of PP-ribose-P and purine ribonucleotides. This critical interaction of PP-ribose-P and purine ribonucleotides may be explained by a change in the physical properties of the enzyme that catalyzes this reaction. The first branch point in the pathway, following this initial step involves the utilization of IMP. Based on an in vitro analysis of the enzymes participating directly in the two biosynthetic pathways for which IMP is a substrate, we propose that the intracellular level of GTP may be more critical than previously recognized.
在当前的讨论中，我们阐述了关于人体中嘌呤从头生物合成如何受到调控的观点。嘌呤核糖核苷酸从头生物合成所特有的起始步骤的速率，由磷酸核糖焦磷酸（PP-核糖-P）和嘌呤核糖核苷酸的细胞内浓度控制。PP-核糖-P与嘌呤核糖核苷酸之间的这种关键相互作用，或许可以通过催化该反应的酶的物理性质变化来解释。在这一起始步骤之后，该途径中的第一个分支点涉及次黄嘌呤核苷酸（IMP）的利用。基于对直接参与以IMP为底物的两条生物合成途径的酶的体外分析，我们提出，鸟苷三磷酸（GTP）的细胞内水平可能比之前认为的更为关键。
