STRUCTURE AND KINETICS OF THE MULTIENZYME COMPLEX OF FATTY ACID OXIDATION FROM ESCHERICHIA COLI (ENZYMOLOGY, PROTEIN, MICROBIOLOGICAL GENETICS).
Item
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Title
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STRUCTURE AND KINETICS OF THE MULTIENZYME COMPLEX OF FATTY ACID OXIDATION FROM ESCHERICHIA COLI (ENZYMOLOGY, PROTEIN, MICROBIOLOGICAL GENETICS).
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Identifier
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AAI8501188
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identifier
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8501188
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Creator
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YANG, SONG-YU.
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Contributor
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Horst Schulz
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Date
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1984
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Biochemistry
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Abstract
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The subunit locations of the five enzymes associated with the fatty acid oxidation complex from E. coli were studied by immunotitration and chemical modification. Antibodies raised against the purified complex caused the parallel inhibitions of enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase, while slightly stimulating 3-ketoacyl-CoA thiolase. All five component enzymes of the complex were inactivated by treatment with iodoacetamide. The inactivation of 3-ketoacyl-CoA thiolase was rapid, whereas the four other enzymes were inactivated at must slower, but almost equal rates. All enzymes except for 3-ketoacyl-CoA thiolase were protected against this inactivation by either NADH or crotonyl-CoA. The reaction of 1-('14)C iodoacetamide with the complex in the presence and absence of NADH resulted in the differential labeling of the large subunit only. These observations together with published results Pawar, S. and H. Schulz (1981) J. Biol. Chem. 256, 3894-3899 lead to the suggestion that enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, cis-(DELTA)('3)-trans-(DELTA)('2)-enoyl-CoA isomerase and 3-hydroxyacyl-CoA epimerase are located on the 78,000-dalton subunit, whereas 3-ketoacyl-CoA thiolase is associated with the 42,000-dalton subunit. Additionally, this study provides further evidence for the existence of a fatty acid oxidation (fab AB) operon that codes for the multienzyme complex of fatty acid oxidation and that is located at 85 min on the E. coli chromosome.;The kinetic properties of the fatty acid oxidation complex from E. coli were studied with the aim of elucidating the functional consequence of having enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase associated with a multifunctional polypeptide. The kinetic parameters of individual enzymes were determined and used in model calculations based on a published theory Storer, A. C. and Cornish-Bowden, A. (1974) Biochem. J. 141, 205-209 to predict the kinetic behavior of a system of functionally unlinked enzymes. The validity of the theory for making these calculations was proven by demonstrating a good agreement between the calculated and observed rates of intermediate and product formation for the conversion of 2-decenoyl-CoA to 3-ketodecanoyl-CoA catalyzed by a mixture of bovine liver enoyl-CoA hydratase and pig heart L-3-hydroxyacyl-CoA dehydrogenase. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biochemistry
