ISSN:
1573-4919
Keywords:
porcine glucokinase
;
purification
;
kinetics
;
sulfhydryl-related states
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Porcine hepatic glucokinase (ATP: D-hexose 6-phosphotransferase EC 2.7.1.1) has been purified by a modification of the procedure for its purification from rats. However, difficulties were encountered with endogenous proteases and the reliability of a source for porcine livers. The molecular weight has been determined to be 60 400 ± 1400 by sodium dodecyl sulfate, polyacrylamide gel electrophoresis. The enzyme has been characterized kinetically. The parameter values, S 0.5 (glucose) and Hill coefficient (nH) are 2.4 mM and 1.9 respectively under sulfhydryl-reducing conditions. The enzyme undergoes the two sulfhydryl-related decays of its activity previously observed in the enzyme isolated from rat (Tippett PS, Neet KE: Arch Biochem Biophys 222:285–298, 1983). The enzyme is inhibited by palmitoyl-CoA, K i (apparent) = 1.0 µM, nH = 1.8; this concentration of inhibitor is significantly below its critical micelle concentration. Physically and kinetically glucokinase isolated from pig is similar to the enzyme isolated from rat. The porcine system provides a second source for isolation and further characterization of this important and unusual enzyme.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00222617
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