Purification and characterization of hypoxanthine/guanine phosphoribosyltransferase in bovine snout epidermis.

ABSTRACT

Hypoxanthine/guanine phosphoribosyltransferase was purified from bovine snout epidermis, about 600-fold by a combination method of centrifugation, ammonium sulfate fraction, Sephadex G-200 and DEAE cellulose chromatography. Enzymatic properties of the purified enzyme were determined as follows pH optimum 7.2, temperature optimum 56 degrees C, and 82,000 in molecular weight. In the presence of phosphoribosyl pyrophosphate, the enzyme was extremely heat-stable. The enzyme displayed Michaelis-Menten kinetics with apparent Michaelis constants for hypoxanthine, guanine and phosphoribosyl pyrophosphate of 1.59, 20.4 and 72.6 microM respectively.