Purification and Characterization of Hypoxanthine/Guanine Phosphoribosyltransferase in Bovine Snout Epidermis

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°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 Michael is constants for hypoxanthine, guanine and phosphoribosyl pyrophosphate of 1.59, 20.4 and 72.6 μM respectivel