TRANS-ALPHA,BETA-DIFORMAMIDO-BETA-(5'-PHOSPHORIBOSYLAMINO)ACRYLAMIDE - POSSIBLE NEW INTERMEDIATE IN DENOVO PURINE BIOSYNTHESIS

被引：3

作者：

BAGGOTT, JE ^{[1
]}

KRUMDIECK, CL ^{[1
]}

机构：

[1] UNIV ALABAMA,DEPT NUTR SCI,BIRMINGHAM,AL 35294

来源：

BIOCHEMISTRY | 1979年 / 18卷 / 16期

关键词：

D O I：

10.1021/bi00583a010

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The nucleotide trans-α, β-diformamido-β-(5′-phosphoribosylamino)acrylamide (DAR) has been chemically synthesized and is converted to inosine 5′-phosphate (IMP) by enzyme activities found in chicken, rat, and human liver. The increase in optical density at 250 nm when DAR is converted to IMP is used as the basis of the assay. The Km values for DAR at pH 7.4 were 2.8 and 4.2 μM with the chicken and rat liver enzymes, respectively. The integrated Michaelis-Menten equation was used to determine the kinetic parameters of the chicken liver enzyme from pH 5.6 to 10.1. The pH-activity profiles show ionizations with pKa values of 6.1, 7.1, and 8.8. The possibilities that DAR is a substrate analogue or a new intermediate in the pathway of purine biosynthesis de novo are discussed. © 1979, American Chemical Society. All rights reserved.

引用

页码：3501 / 3506

页数：6

共 19 条

[1] FOLYLPOLY-GAMMA-GLUTAMATES AS CO-SUBSTRATES OF 10-FORMYLTETRAHYDROFOLATE-5'-PHOSPHORIBOSYL-5-AMINO-4-IMIDAZOLE-CARBOXAMIDE FORMYLTRANSFERASE [J].