Pyruvate inhibition

The reactions of Eq. 15-19 occur nonenzymatically only under the influence of strong base but dehydrogenases often catalyze similar condensations relatively rapidly and reversibly. Pyruvate inhibits lactate dehydrogenase, 2-oxoglutarate inhibits glutamate dehydrogenase, and ketones inhibit a short-chain alcohol dehydrogenase in this manner.133,693... 

Colsky AS, Peacock JS. 1990. Sodium pyruvate inhibits the spontaneous release of 51Cr from RBC in chromium release assays. J Immunol Methods 129 139-141. 

The same workers looked at the pH dependence of pyruvate inhibition and reported p/ifa values of 7.3 and 8.0 (95). They suggested that the p/ifa of 7.3 was essentially that of the same group involved in l-lactate binding for which the piifa was determined as 6.7. This would require a residue capable of binding to both an a-hydroxyl and an a-keto group ... 

Stanko, R. T., Sekas, G., Isaacson, I. A., Qarke, M. R., BilUar, T. R., and Paul, H. S. (1995). Pyruvate inhibits clofibrate-induced hepatic peroxisomal proliferation and free radical production in rats. 

Pyruvate inhibition of lactate dehydrogenases (3,56) has attracted much attention and shows unusual features. The fact that the heart isozymes from several species are more susceptible to the inhibition than muscle isozymes, in vitro, has been correlated with distinct functional roles for the enzymes in highly aerobic heart muscle and in glycolyzing voluntary muscle, particularly by Kaplan (79,100), but it has been disputed whether these differences are significant under physiological condi-... 

Various reasons for the advantages gained in the specialization of major LDH isozymes have been proposed (68,69,71-74) One possibility may be in the greater degree of pyruvate inhibition of the H4 isozyme (1,36,69) as a result of the formation of the abortive ternary LDH NAD-pyruvate complex (see Section III,C,3). 

Pratt, T.E. Roche, T.E. Mechanism of pyruvate inhibition of kidney pyruvate dehydrogenase kinase and synergistic inhibition by pyruvate and ADP. J. Biol. Chem., 254, 7191-7196 (1979)... 

Schuller, K.A. Randall, D.D. Mechanism of pyruvate inhibition of plant pyruvate dehydrogenase kinase and synergism with ADP. Arch. Biochem. Biophys., 278, 211-216 (1990)... 

Pyruvate inhibits the oxidation of tyrosine and p-hydroxyphenyl-pyruvate, but not of homogentisic acid. This inhibition can be reversed by ascorbic acid or hydroquinone and its site of action, then, appears to be in relation to 2,5-dihydroxyphenyl formation from p-hydroxyphenyl-pyruvate. 

Kluge and Osmond (1972) reported malate and pyruvate inhibition of partially purified PEP carboxylase from Kalanchoe tubiflora and Sedum praealtum with a Ki for malate of 3.6 mM at pH 6.25 (Fig. 4.2). Since malate may accumulate to a level of 100 pmol per g fresh weight in crassulacean plants, 1% of this concentration in the vicinity of PEP carboxylase would be sufficient for inhibition. 

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