RADIOASSAY OF BIFUNCTIONAL 5-AMINOIMIDAZOLE-4-CARBOXAMIDE RIBOTIDE TRANSFORMYLASE-IMP CYCLOHYDROLASE BY THIN-LAYER CHROMATOGRAPHY

被引：10

作者：

SZABADOS, E ^{[1
]}

CHRISTOPHERSON, RI ^{[1
]}

机构：

[1] UNIV SYDNEY,DEPT BIOCHEM,SYDNEY,NSW 2006,AUSTRALIA

来源：

ANALYTICAL BIOCHEMISTRY | 1994年 / 221卷 / 02期

关键词：

D O I：

10.1006/abio.1994.1433

中图分类号：

Q5 [生物化学];

学科分类号：

071010 ; 081704 ;

摘要：

A radioassay has been developed for the bifunctional enzyme, AICAR transformylase-IMP cyclohydrolase, which catalyzes reactions 9 and 10 of the de novo pathway for biosynthesis of purine nucleotides (AICAR --> FAICAR --> IMP). H-3-labeled AICAR or FAICAR is converted enzymically to product(s) which are separated by one-dimensional thin-layer chromatography prior to quantification by scintillation counting. Using this sensitive radioassay, a dissociation constant of IMP cyclohydrolase for FAICAR of 0.87 mu M has been determined and AICAR, FAICAR, and IMP can be quantified in assay mixtures for AICAR transformylase-IMP cyclohydrolase. The ratio of specific enzymic activities for AICAR transformylase:IMP cyclohydrolase is 1:44. (C) 1994 Academic Press, Inc.

引用

页码：401 / 404

页数：4

共 9 条

[1] INHIBITION OF PHOSPHORIBOSYLAMINOIMIDAZOLECARBOXAMIDE TRANSFORMYLASE BY METHOTREXATE AND DIHYDROFOLIC ACID POLYGLUTAMATES [J].