Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) was isolated from the malarial parasite, Plasmodium lophurae. The apparent pI, as determined by chromatofocusing, was 7.6. The native molecular weight was 79,000. The pH profile of HGPRT exhibited a broad pH optimum. With hypoxanthine as substrate maximal activity was achieved from pH 6.0-10.0, and with guanine as substrate maximal activity occurred from pH 7.5-9.5. The enzyme exhibited Michaelis-Menten kinetics with all substrates. The Km values were 3.8 microM (hypoxanthine), 2.4 microM (guanine), 6.2 microM (6-mercaptopurine), 7.6 microM (6-thioguanine), and 360 microM (8-azahypoxanthine). 6-Thioinosine, 9-beta-arabinofuranosylhypoxanthine, 6-chloropurine, xanthine and azaguanine were inhibitors of the P. lophurae enzyme. From the substrate and inhibitor data it appears that the sixth position on the purine ring plays a major role in enzyme activity.
 ...
PMID:Purification of hypoxanthine-guanine phosphoribosyltransferase of Plasmodium lophurae. 357 49