Spectral shifts of cytochrome c oxidase induced by complexons

FEBS Letters

Berka, Vladimir²  Musatov, Andrey²  Popova, Eugenia¹  Konstantinov, Alexander¹  Vygodina, Tatiana¹ 

[1] A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Moscow 119899, USSR;Laboratory of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Solovjevova 47, 04353 Kosice, Czechoslovakia

关键词: Cytochrome-c oxidase;    Conformational change;    ATP;    Spectral shift;    Complexon;    Metal ion binding;   

DOI  :  10.1016/0014-5793(89)80187-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ca²⁺-chelating agents, such as EDTA and ATP, are shown to bring about a rapid spectral response of the oxidized cytochrome c oxidase due to reversal of the Ca²⁺-induced red shift of the γ- and α-absorption bands of the ferric enzyme. In addition, complexons are found to bring about Ca²⁺-independent, slow irreversible spectral changes indicative of a conformational transition of cytochrome oxidase. 1 mol EDTA per mol enzyme is sufficient to produce the maximal effect even in the presence of excess Ca²⁺, indicating high specificity of interaction. It is suggested that the conformation of cytochrome c oxidase may be regulated by the tightly bound ‘non-redox’ metal ions (Mg, Zn, Cu _x ) known to be present in the enzyme. These ions might be involved in specific binding of physiological effectors with chelating properties, such as ATP.

【 授权许可】

Unknown