The biosynthesis of nicotinamide adenine dinucleotide. IV. The isolation and physico-chemical properties of crystalline quinolinate phosphoribosyltransferase from hog liver.

Abstract

Quinolinate phosphoribosyltransferase (an intermediary enzyme in the de novo NAD biosynthetic pathway) was purified from hog liver and its crystallization from a mammal was successful for the first time. This crystalline enzyme preparation was certified to be homogeneous by ultracentrifugal analysis and polyacrylamide gel disc electrophoresis. Its molecular weight was 173,000 using the gel filtration method, and 172,000 using sedimentation velocity analysis. The subunit molecular weight was estimated at 33,500 with SDS polyacrylamide gel disc electrophoresis. Several physico-chemical parameters were also determined.