Parameswaran Saravanan, Dubey Vikash Kumar, Patra Sanjukta
Department of Biotechnology, Indian Institute of Technology Guwahati, Assam, India.
In Silico Biol. 2010;10(5-6):265-76. doi: 10.3233/ISB-2010-0438.
Bacterial true lipases having thermo and alkaline stability are highly attractive for their industrial production of pharmaceuticals, agrochemicals, cosmetics, and flavour. Staphylococcus aureus lipase (SAL3) remains active at temperatures 40-60°C, with an optimum temperature of 55°C and an optimum pH of 9.5 stable over a range of 5-12. Detailed understanding of the structure and insight into the activity of such lipase would aid in engineering lipases that would function in the desired extreme industrial environments. In the present study, we carried out in silico characterization and structural modeling of SAL3 which is thermoactive, alkaline and detergent-stable. Comparison of SAL3 with other staphylococcal lipases indicates that SAL3 is a true lipase having the catalytic triad (residues Ser119, Asp310 & His352) and the calcium binding site (residues Asp351, Asp354, Asp359, Asp362 and Gly286). Conservation in sequence implies that interfacial activation mechanism is possible in SAL3 with the lid formed by helix (residues 180-196) and loop (residues 197-206). Three dimensional (3D) structure model of SAL3 has been predicted for the first time and aims at understanding its function and biochemical characteristics of possessing relatively high thermal and pH stability.
具有热稳定性和碱性稳定性的细菌真性脂肪酶在药物、农用化学品、化妆品和香料的工业生产中极具吸引力。金黄色葡萄球菌脂肪酶（SAL3）在40-60°C的温度下仍保持活性，最适温度为55°C，最适pH为9.5，在5-12的范围内稳定。对这种脂肪酶的结构进行详细了解并深入了解其活性，将有助于设计出能在理想的极端工业环境中发挥作用的脂肪酶。在本研究中，我们对具有热活性、碱性和洗涤剂稳定性的SAL3进行了计算机表征和结构建模。将SAL3与其他葡萄球菌脂肪酶进行比较表明，SAL3是一种具有催化三联体（Ser119、Asp310和His352残基）和钙结合位点（Asp351、Asp354、Asp359、Asp362和Gly286残基）的真性脂肪酶。序列保守性表明，SAL3可能存在由螺旋（180-196残基）和环（197-206残基）形成的盖子的界面激活机制。首次预测了SAL3的三维（3D）结构模型，旨在了解其功能以及具有相对较高热稳定性和pH稳定性的生化特性。
