Kinetic Studies of Ferrous Ion Oxidation with Crystalline Human Ferroxidase (Ceruloplasmin)
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منابع مشابه
Kinetic studies of ferrous ion oxidation with crystalline human ferroxidase (ceruloplasmin).
The kinetics of the catalysis of Fe(I1) oxidation by crystalline human ferroxidase (ceruloplasmin) has been studied under various conditions at 30’. Two Km values with respect to Fe(U), Km1 = 0.6 /.tM and Km2 = 50 PM, were obtained at pH 6.5, at which ferroxidase gave the maximum activity of 550 Fe(I1) per ferroxidase per min in an acetate buffer. Competition between the two substrates, p-pheny...
متن کاملKinetic studies of ferrous ion oxidation with crystalline human ferroxidase. II. Rate constants at various steps and formation of a possible enzyme-substrate complex.
The reaction between crystalline human ferroxidase (ferro:On oxido-reductase, EC 1.12.3) and the substrate, Fe(H), was studied by a stop-flow method. The rate constants for four separate steps-enzyme-substrate complex formation, separation of product from the enzyme, reoxidation by molecular oxygen, and a rate-determining step-were estimated to be kl = 1.2 x lo6 M-I set-I, kp = 13 set-*, ka = 5...
متن کاملinhibition of human ceruloplasmin (ferroxidase) by cadmium
ceruloplasmin (cp) is a human plasma protein with multiple physiological functions including ferroxidase and oxidase activities. deficiency or inhibition of the enzyme may lead to some abnormalities, including iron deposition in several tissues and causes various pathological conditions in the body. direct interaction of cadmium (cd), a widespread, highly toxic environmental pollutant, with hum...
متن کاملFerroxidase activity of rat ceruloplasmin.
WILLIAMS, ID. M., G. K. LEE, AND G. E CARTWRIGIIT. Fb-roxidasc nctivity of rat ccruloplasmin. Am. J. Physiol. 227(5) : 1094-1097. 1974.-The ferroxidase activity of rat ceruloplasmin was studied under various assay conditions. The ferroxidase activity was optimal at pH 6.0-6.2 in acetate buffer in the absence of ascorbate, and under these conditions the activity was about 1/3rd that of human cer...
متن کاملImmunochemical studies of crystalline human ceruloplasmin and derivatives.
Previous immunochemical investigations of ceruloplasmin have been primarily concerned with the assay of this substance in human sera and its localization by the technique of immunoelectrophoresis. The proteins used in the preparation of antisera appear to have been impure or poorly defined. The ready availability of crystalline human ceruloplasmin (I, 2) prompted us to study its immunochemical ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1966
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)99669-9