Kushwaha Madhulika, Kumar Virender, Mahajan Rishi, Bhalla Tek Chand, Chatterjee Subhankar, Akhter Yusuf
Bioremediation and Metabolomics Research group, Department of Environmental Sciences, Central University of Himachal Pradesh, Kangra, Himachal Pradesh, 176206, India.
Department of Biotechnology, Himachal Pradesh University, Summer Hill, Shimla, 171005, India.
Arch Microbiol. 2018 Aug;200(6):971-977. doi: 10.1007/s00203-018-1524-0. Epub 2018 May 9.
The present study provides molecular insights into the activity and mechanism of cyanide hydratase enzyme associated with degradation of cyanide compounds, using Serratia marcescens RL2b as a model organism. Resting cells harvested after 20 h achieved complete degradation of 12 mmol l cyanide in approximately 10 h. High-performance liquid chromatography analysis of reaction samples revealed formation of formamide as the only end product, which confirmed the presence of cyanide hydratase activity in S. marcescens RL2b. Comparative structural analysis with the other nitrilase family proteins, which was carried out using a sequence of cyanide hydratase from a phylogenetically related strain S. marcescens WW4, also revealed subtle but significant differences in amino acid residues of the substrate-binding pocket and catalytic triad (Cys-Lys-Glu).
本研究以粘质沙雷氏菌RL2b为模式生物，对与氰化物化合物降解相关的氰化氢酶的活性和机制进行了分子层面的深入研究。20小时后收获的静息细胞在约10小时内实现了12 mmol/L氰化物的完全降解。对反应样品进行的高效液相色谱分析表明，仅生成了甲酰胺作为唯一的终产物，这证实了粘质沙雷氏菌RL2b中存在氰化氢酶活性。使用来自系统发育相关菌株粘质沙雷氏菌WW4的氰化氢酶序列，与其他腈水解酶家族蛋白进行的比较结构分析也揭示了底物结合口袋和催化三联体（半胱氨酸-赖氨酸-谷氨酸）的氨基酸残基存在细微但显著的差异。
