Whited Charlotte A, Warren Jeffrey J, Lavoie Katherine D, Winkler Jay R, Gray Harry B
Beckman Institute, California Institute of Technology, Pasadena, CA 91125.
Polyhedron. 2013 Jul 13;58:134-138. doi: 10.1016/j.poly.2012.08.079.
We report the kinetics of CO rebinding to the heme in His134Ser, Ile223Val and His134Ser/Ile223Ser mutants of nitric oxide synthase (gsNOS). The amplitudes of the two observed kinetics phases, which are insensitive to CO concentration, depend on enzyme concentration. We suggest that two forms of gsNOS are in equilibrium under the conditions employed (6.1-27 µM gsNOS with 20 or 100% CO atmosphere). The kinetics of CO rebinding to the heme do not depend on the identity of the NO-gate residues at positions 134 and 223.
我们报告了一氧化碳（CO）与一氧化氮合酶（gsNOS）的His134Ser、Ile223Val和His134Ser/Ile223Ser突变体中血红素重新结合的动力学。观察到的两个动力学阶段的幅度对CO浓度不敏感，取决于酶浓度。我们认为，在所采用的条件下（6.1 - 27 μM gsNOS，处于20%或100% CO气氛中），两种形式的gsNOS处于平衡状态。CO与血红素重新结合的动力学不取决于134和223位的NO门控残基的特性。
