Environmental Biotechnology Division, Indian Institute of Toxicology Research, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh 226001, India.
Int J Biol Macromol. 2010 Jan 1;46(1):47-53. doi: 10.1016/j.ijbiomac.2009.10.014. Epub 2009 Oct 30.
Biphenyl dioxygenase is a microbial enzyme which catalyzes the stereospecific dioxygenation of aromatic rings of biphenyl congeners leading to their degradation. Hence, it has attracted the attention of researchers due to its ability to oxidize chlorinated biphenyls, which are one of the serious environmental contaminants. In the present study, the three-dimensional model of alpha-subunit of biphenyl dioxygenase (BphA) from Comamonas testosteroni B-356 has been constructed. The resulting model was further validated and used for docking studies with a class of chlorinated biphenyls such as biphenyl,3,3'-dichlorobiphenyl and 4,4'-dichlorobiphenyl. The kinetic parameters of these biphenyl compounds were well matched with the docking results in terms of conformational and distance constraints. The binding properties of these biphenyl compounds along with identification of critical active site residues could be used for further site-directed mutagenesis experiments in order to identify their role in activity and substrate specificity, ultimately leading to improved mutants for degradation of these toxic compounds.
联苯双加氧酶是一种微生物酶，能够立体特异性地催化联苯同类物的芳环双加氧，从而导致其降解。因此，由于其能够氧化氯代联苯的能力，这种酶引起了研究人员的关注，而氯代联苯是一种严重的环境污染物。在本研究中，构建了来自康宁氏杆菌 B-356 的联苯双加氧酶（BphA）的α-亚基的三维模型。所得模型进一步经过验证，并用于与一类氯代联苯（如联苯、3,3'-二氯联苯和 4,4'-二氯联苯）的对接研究。这些联苯化合物的动力学参数与对接结果在构象和距离约束方面非常匹配。这些联苯化合物的结合特性以及关键活性位点残基的鉴定可用于进一步的定点突变实验，以确定它们在活性和底物特异性中的作用，最终导致这些有毒化合物的降解的改良突变体。
