Kunz D A, Fernandez R F, Parab P
Department of Biological Science, University of North Texas, Denton, Texas 76203-5220, USA.
Biochem Biophys Res Commun. 2001 Sep 21;287(2):514-8. doi: 10.1006/bbrc.2001.5611.
The soluble cell-free fraction (150,000g high-speed supernatants [HSS]) of Pseudomonas fluorescens NCIMB 11764 contains putative cyanide oxygenase (CNO) responsible for initiating cyanide oxidation and assimilation as a nitrogenous growth substrate. CNO activity, assayed either by cyanide-dependent O(2) or NADH uptake, or by conversion of radioactive K(14)CN to (14)CO(2), was detected at micromolar concentrations (apparent half-saturation constant, 4 microM). Results demonstrating that CNO requires a protein-enriched cell fraction and a low MW redox factor (<500 Da) for which reduced biopterin could substitute are presented. The properties of CNO are consistent with those of a pterin hydroxylase.
荧光假单胞菌NCIMB 11764的可溶性无细胞组分(150,000g高速上清液[HSS])含有假定的氰化物加氧酶(CNO),该酶负责启动氰化物氧化并将其同化为含氮生长底物。通过氰化物依赖性O(2)或NADH摄取,或通过将放射性K(14)CN转化为(14)CO(2)来测定CNO活性,在微摩尔浓度下(表观半饱和常数,4 microM)检测到该活性。结果表明,CNO需要富含蛋白质的细胞组分和低分子量氧化还原因子(<500 Da),还原型生物蝶呤可以替代该因子。CNO的特性与蝶呤羟化酶的特性一致。