Sejlitz T, Neujahr H Y
Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
Eur J Biochem. 1987 Dec 30;170(1-2):343-9. doi: 10.1111/j.1432-1033.1987.tb13705.x.
The binding of phenol to phenol hydroxylase was studied by equilibrium dialysis, spectrophotometric titration and by steady-state kinetics. A binding model with two identical, negatively cooperative, effector/substrate-binding sites per enzyme dimer is proposed. The spectral perturbation caused by phenol and the kinetics of the overall reaction were analysed with relation to the enzyme-phenol complexes of the binding model. The main part of the spectral perturbation as well as of the increase in NADPH oxidation rate was achieved by one molecule of phenol bound per enzyme dimer. The properties of different enzyme-phenol complexes, in terms of spectral changes, hydroxylase activity, oxidase activity and substrate inhibition are discussed. A new purification procedure is described.
通过平衡透析、分光光度滴定和稳态动力学研究了苯酚与苯酚羟化酶的结合。提出了一个结合模型，每个酶二聚体有两个相同的、负协同的效应物/底物结合位点。根据结合模型的酶-苯酚复合物分析了苯酚引起的光谱扰动和总反应动力学。光谱扰动的主要部分以及NADPH氧化速率的增加是由每个酶二聚体结合一分子苯酚实现的。讨论了不同酶-苯酚复合物在光谱变化、羟化酶活性、氧化酶活性和底物抑制方面的性质。描述了一种新的纯化方法。
