Biochemical and biophysical studies on cytochrome c oxidase. XIII. Effect of cholate on the enzymic activity.
(1) Cholate is a mixed-type inhibitor of the enzymic activity of cytochrome c oxidase. The rate equations for mixed-type inhibition of the enzyme have been derived, based on Minnaert's Mechanism IV (1961, Biochim. Biophys. Acta 50, 23-34). The Ki of cholate for the free enzyme (E) and for the complexes of the enzyme with cytochrome c (ES and EP) was determined, being 125 and 190 microM, respectively. (2) Comparison of the properties of cholate and the intrinsic inhibitor of cytochrome c oxidase (Van Buuren et al. (1971) Biochim. Biophys. Acta 243, 468-480) with respect to their type of inhibition and their affinity for enzyme, reveals that they are identical.
Van Buuren
K J
KJ
Laboratory of Biochemistry, B. C. P. Jansen Institute, University of Amsterdam, Plantage Muidergracht 12, Amsterdam, The Netherlands.
Van Gelder
B F
BF
D000818:Animals; D020355:Cholates / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000737:chemistry / Q000378:metabolism; D003902:Detergents / Q000737:chemistry; D003576:Electron Transport Complex IV / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D006736:Horses; D008929:Mitochondria, Heart / Q000201:enzymology
D020355:Cholates; D003902:Detergents; D003840:Deoxycholic Acid; D003576:Electron Transport Complex IV