Glucosamine-6-phosphate deaminase from beef kidney is an allosteric system of the V-type.
The enzyme glucosamine-6-phosphate deaminase from beef kidney has been purified to homogeneity by allosteric-site affinity chromatography. Its amino acid composition and the N-terminal sequence (1-42), were obtained. The amino acid sequence of this segment is essentially identical to the corresponding regions of the human and hamster glucosamine-6-phosphate deaminases. The beef enzyme is a hexamer of 32.5 kDa subunits; this is nearly 2.5 kDa higher than the molecular mass of the homologous enzyme from Escherichia coli. Beef kidney deaminase exhibits a notable difference from the bacterial enzyme in its allosteric activation by N-acetylglucosamine 6-phosphate This metabolite, which is also is the allosteric activator of the bacterial glucosamine-6-phosphate deaminase, activates the enzyme by increasing its kcat without any change in the Km values for glucosamine 6-phosphate, over a wide range of activator concentration. This observation places beef kidney deaminase in the class of V-type allosteric systems.
Lara-Lemus
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Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, P.O. Box 70-159, Ciudad Universitaria, 04510 Mexico City, DF, Mexico.
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D019747:Aldose-Ketose Isomerases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002846:Chromatography, Affinity; D006224:Cricetinae; D005944:Glucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment
C001293:glucosamine 6-phosphate; D019298:Glucose-6-Phosphate; C020582:glucosamine-6-phosphate isomerase; D019747:Aldose-Ketose Isomerases; D005944:Glucosamine