Selenomethionine as substrate for glutamine transaminase.
Selenomethionine is as a good substrate as methionine for bovine liver glutamine transaminase (E.C. 2.6.1.15). Almost identical Km values for methionine, selenomethionine, 4-methylthio-2-oxobutanoic acid and 4-methylseleno-2-oxobutanoic acid have been obtained. Like for other enzymes, also for glutamine transaminase the substitution of the sulfur atom in a substrate molecule by a selenium one does not appreciably affect the enzyme affinity. Glutamine transaminase may thus be involved in selenomethionine catabolism.
Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Università La Sapienza, Roma, Italy.
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D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008715:Methionine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D012645:Selenomethionine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity; D000637:Transaminases / Q000378:metabolism*
C087942:4-methylseleno-2-oxobutanoic acid; C014632:2-keto-4-methylthiobutyric acid; D012645:Selenomethionine; D008715:Methionine; D000637:Transaminases; C020656:glutamine-pyruvate aminotransferase