Abstract
Summary
The enzymatic hydrolysis of glucose 1-phosphate (G1P) and glucose 6-phosphate (G6P) by homogenates of rat intestinal mucosa was quantitated. These substrates were not utilized by enzymes other than phosphatases to any appreciable extent. The mean K m value for the hydrolysis of G6P was higher (4.3 mM) than that for G1P (1.69 mM). A variability was observed in Km values in each substrate group. However, the Km /Vmax ratio was constant for each of the two substrates. Such proportional changes in Km and Vmax values allow the approximation of the rate constant (K 1) related to the formation of the enzyme-substrate complex. The K 1 value thus estimated for G1P was approximately 1.68 times that for G6P.
This work was supported by U. S. Army Research and Development Command, Department of the Army, under Research Contract No. DA-49-193-MD-2415, and by Research Grant AM 11945 from the National Institutes of Health, U. S. Public Health Service.
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