Littlechild Jennifer, Garcia Rodriguez Esther, Isupov Mikhail
School of Biosciences, University of Exeter, Exeter, UK.
J Inorg Biochem. 2009 Apr;103(4):617-21. doi: 10.1016/j.jinorgbio.2009.01.011. Epub 2009 Jan 25.
The X-ray crystal structure of the vanadium bromoperoxidase from the red algae Corallina pilulifera has been solved in the presence of the known substrates, phenol red and phloroglucinol. A putative substrate binding site has been observed in the active site channel of the enzyme. In addition bromide has been soaked into the crystals and it has been shown to bind unambiguously within the enzyme active site by using the technique of single anomalous dispersion. A specific leucine amino acid is seen to move towards the bromide ion in the wild-type enzyme to produce a hydrophobic environment within the active site. A mutant of the enzyme where arginine 397 has been changed to tryptophan, shows a different behaviour on bromide binding. These results have increased our understanding of the mechanism of the vanadium bromoperoxidases and have demonstrated that the substrate and bromide are specifically bound to the enzyme active site.
在已知底物酚红和间苯三酚存在的情况下，已解析出红藻珊瑚藻中钒溴过氧化物酶的X射线晶体结构。在该酶的活性位点通道中观察到一个假定的底物结合位点。此外，溴化物已被浸泡到晶体中，通过单异常色散技术已证明它明确地结合在酶的活性位点内。在野生型酶中，可见一个特定的亮氨酸氨基酸向溴离子移动，以在活性位点内产生疏水环境。将精氨酸397替换为色氨酸的该酶突变体，在结合溴化物时表现出不同的行为。这些结果增进了我们对钒溴过氧化物酶作用机制的理解，并证明底物和溴化物特异性地结合到酶的活性位点。
