Hüther F J, Berden J, Kadenbach B
Biochemie, Fachbereich Chemie der Philipps-Universität Hans-Meerwein-Strasse, Marburg, FRG.
J Bioenerg Biomembr. 1988 Aug;20(4):503-16. doi: 10.1007/BF00762206.
The effect of ATP and other anions on the kinetics of cytochrome c oxidation by reconstituted bovine heart cytochrome c oxidase was investigated. The following results were obtained: (1) ATP and other polyvalent anions increase the Km for cytochrome c and the Vmax (if assayed by the photometric method). The magnitude of the effect is proportional to the charge of the anion as follows from the series of increasing effectiveness: Pi less than AMP less than ADP less than PPi less than ATP less than PPPi. (2) The kinetic effects are obtained in the millimolar physiological concentration range. (3) The kinetic changes are not saturated at high concentrations. (4) A specific interaction site for ATP at the cytosolic domain of the enzyme is concluded from the increase of Km for cytochrome c after photolabelling of proteoliposomes with 8-azido-[gamma-32P]-ATP, which is protected by ATP but not by ADP. (5) No specific "binding site" for ATP could be identified by photolabelling with 8-azido-[gamma-32P]-ATP. The labelling is only partly protected by ATP or ADP.
研究了ATP和其他阴离子对重组牛心脏细胞色素c氧化酶催化细胞色素c氧化动力学的影响。得到以下结果：（1）ATP和其他多价阴离子增加细胞色素c的Km值和Vmax（如果用光度法测定）。效应的大小与阴离子的电荷成正比，从有效性增加的系列来看：磷酸根小于AMP小于ADP小于焦磷酸小于ATP小于三磷酸焦磷酸。（2）在毫摩尔生理浓度范围内获得动力学效应。（3）在高浓度下动力学变化不饱和。（4）在用8-叠氮基-[γ-32P]-ATP对蛋白脂质体进行光标记后，细胞色素c的Km增加，由此得出该酶胞质结构域存在ATP的特异性相互作用位点，该位点受ATP保护但不受ADP保护。（5）用8-叠氮基-[γ-32P]-ATP进行光标记未鉴定出ATP的特异性“结合位点”。标记仅部分受ATP或ADP保护。
