马红球菌(Rhodococcus equi)SHB-121胞内3-氰基吡啶水合酶经硫酸铵分级沉淀、DEAE-cellulose DE52和羟基磷灰石柱层析并经过Sephadex G-25处理,得到了聚丙烯酰胺凝胶电泳均一的3-氰基吡啶水合酶,纯化了31倍。该酶由一条肽链组成,其分子量为30kD,等电点为4.1。3-氰基吡啶水合酶能催化3-氰基吡啶水合生成尼克酰胺。酶反应最适pH为8.0,最适温度为30℃。Ag~+、Hg~(2+)、Cu~(2+)及NH_4~+对酶活力有强烈抑制作用。当以3-氰基吡啶为底物时,其K_m为0.1mol/L。NaCN为该酶反竞争性抑制剂,其K_i为5mmol/L。 Rhodococcus equi SHB-121 intracellular 3-cyanopyridine hydratase was fractionated by ammonium sulfate, chromatographed on DEAE-cellulose DE52 and hydroxyapatite and subjected to Sephadex G-25 treatment to obtain polyacrylamide The homogeneous 3-cyanopyridine hydratase gel was electrophoresed 31 times. The enzyme consists of a peptide chain with a molecular weight of 30 kD and an isoelectric point of 4.1. 3-cyanopyridine hydratase catalyzes the hydration of 3-cyanopyridine to nicotinamide. The optimum pH of enzyme reaction was 8.0 and the optimum temperature was 30 ℃. Ag ~ +, Hg ~ (2 +), Cu ~ (2+) and NH_4 ~ + had a strong inhibitory effect on the enzyme activity. When using 3-cyanopyridine as a substrate, its Km is 0.1mol / L. NaCN is an anti-competitive inhibitor of this enzyme with a K_i of 5 mmol / L.