Glucosamine-6-phosphate deaminase from beef kidney is an allosteric system of the V-type
Por:
Lara-Lemus R., Calcagno M.L.
Publicada:
1 ene 1998
Resumen:
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 k(cat) without any change in the K(m) 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. Copyright (C) 1998 Elsevier Science B.V.
Filiaciones:
Lara-Lemus R.:
Departamento de Bioquímica, Fac. de Med., Univ. Nac. A., 04510 Mexico City, DF, Mexico
Calcagno M.L.:
Departamento de Bioquímica, Fac. de Med., Univ. Nac. A., 04510 Mexico City, DF, Mexico
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