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J H Ottaway

Publications and source records attributed to J H Ottaway.

11 recordsLinked to original sources
PubMed1977

Studies on the mechanism and kinetics of the 2-oxoglutarate dehydrogenase system from pig heart.

1. The kinetic properties of the 2-oxoglutarate dehydrogenase system were investigated. To this end, initial-velocity studies were carried out by the method of Fromm [(1967) Biochim. Biophys. Acta 139, 221-230]. Reciprocal plots of the results did not agree with those expected for the Hexa Uni Ping Pong mechanism previously proposed for the system. 2. The measured initial velocities were fitted to initial-rate equations corresponding to several possible mechanisms by using a computer optimization technique. Statistical analyses performed on the results of the optimization studies indicated that one mechanism was a significantly better fit to the experimental data than the other mechanisms tested. This mechanism is one in which there is a random order of binding of NAD+ and CoA and release of succinyl-CoA, although the binding of 2-oxoglutarate and release of CO2 is still given a Ping Pong mechanism, which precedes the binding of the other substrates. These conclusions were supported by NADH-inhibition studies. 3. The usefulness of the method of fitting initial-rate data to rate equations and the applicability of the proposed enzymic mechanism to the enzyme complex are discussed.

Animals↗
PubMed1975

Localization in cardiac muscle of some enzymes related to glutamate metabolism.

A tetrazolium staining medium incorporated in a gel has been used in a histochemical study of enzymes in thin sections of heart muscle. Formazan distribution patterns given by mitochondrial enzymes were inconsistent with the location of these enzymes revealed by the extraction of whole tissue. Similar stain distributions were given by lactate dehydrogenase, glutamate oxaloacetate transaminase and glutamate dehydrogenase. The distribution given by succinate dehydrogenase was not the same as that given by cytochrome oxidase stained by a different technique. Alcohol dehydrogenase added to the tissue assumed a distribution which suggested some adsorption of the enzyme to the tissue. But experiments suggested that this enzyme was not firmly bound to muscle proteins in the manner of some glycolytic enzymes.

Alcohol Oxidoreductases↗