Early reduction of cytochrome c in hypoxia

FEBS Letters

Chance, B.¹ 

[1] Department of Biochemistry and Biophysics, University of Pennsylvania and Institute for Structural and Functional Studies, University City Science Center, Philadelphia, PA 19104, USA

关键词: Steady state;    Cytochrome a;    Cytochrome a 3;    Cytochrome c;    Cytochrome oxidase;    Oxygen affinity;    (Yeast cell);   

DOI  :  10.1016/0014-5793(88)81451-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Shifts of the steady state of cytochromes a, a ₃ and c at high pO₂ values are cited as evidence of the low O₂ affinity of cytochrome oxidase in vivo [(1971) Brain Res. 108, 143–154; (1985) Adv. Exp. Med. Biol. 191, 833–842; (1987) in: Int. Soc. Oxygen Transp. Tissue, Sapporo, p. 84]. Highly aerobic, small diploid yeast cells show <0.44% change of steady state in the interval prior to an abrupt reduction of cytochrome c. Thus, ‘pre-reduction’ seems falsified as a physiological response of metabolizing yeast cells that are free of hemoglobin, do not aggregate and maintain a steady state. Pre-reduction may be due to spectroscopic interference, for example hemoglobin deoxygenation, to oxygen gradients in aggregated cells and tissues or to non-steady states of substrate and metabolic controls, as contrasted to an altered cytochrome oxidase oxygen affinity in vivo.

【 授权许可】

Unknown