Choudhry Z M, Kotlyar A B, Vinogradov A D
Biochim Biophys Acta. 1986 Jun 10;850(1):131-8. doi: 10.1016/0005-2728(86)90017-4.
The inhibitory effect of pyridoxal phosphate on the Triton X-100 solubilized purified bovine heart succinate-ubiquinone reductase (Choudhry, Z.M., Gavrikova, E.V., Kotlyar, A.B., Tushurashvilli, P.R. and Vinogradov, A.D. (1985) FEBS Lett. 182, 171-175) was studied. The kinetics of the enzyme inactivation by pyridoxal phosphate was found to be strongly dependent both qualitatively and quantitatively on the concentration of the protein-detergent complexes. In the diluted system the inactivation of the ubiquinone-depleted enzyme was completely prevented by the saturating concentrations of Q2, carboxin, thenoiltrifluoroacetone and pentachlorophenol, i.e., by the substrate and specific inhibitors of the enzyme. The protective effects of Q2 and the inhibitors was employed to quantitate the affinities of the ligands to their specific binding sites. Strong difference in the affinity of Q2 to the reduced and oxidized enzyme was found. When the soluble reconstitutively active succinate dehydrogenase was treated with pyridoxal phosphate, the reactivity of the enzyme towards low ferricyanide concentrations and its reconstitutive activity was significantly protected against aerobic inactivation.
研究了磷酸吡哆醛对Triton X - 100增溶的纯化牛心琥珀酸 - 泛醌还原酶的抑制作用（乔德里，Z.M.，加夫里科娃，E.V.，科特利亚尔，A.B.，图舒拉什维利，P.R.和维诺格拉多夫，A.D.（1985年）《欧洲生物化学学会联合会快报》182，171 - 175）。发现磷酸吡哆醛使该酶失活的动力学在定性和定量上都强烈依赖于蛋白质 - 去污剂复合物的浓度。在稀释系统中，饱和浓度的Q2、羧菌灵、噻菌灵三氟丙酮和五氯苯酚，即该酶的底物和特异性抑制剂，完全阻止了泛醌耗尽酶的失活。利用Q2和抑制剂的保护作用来定量配体与其特异性结合位点的亲和力。发现Q2与还原型和氧化型酶的亲和力存在很大差异。当用磷酸吡哆醛处理可溶性重组活性琥珀酸脱氢酶时，该酶对低浓度铁氰化物的反应性及其重组活性在有氧失活过程中得到了显著保护。
