Title: Studies on the phosphoglucosaminisomerase reaction of Escherichia coli
Abstract: 1. The mechanism for the conversion of glucosamine 6-phosphate to fructose 6-phosphate and ammonia has been studied using a purified enzyme isolated from Escherichia coli. 2. Of the various compounds tested, only N-acetylglucosamine-6-PO4 was found to be stimulatory; the products of the reaction, fructose-6-PO4 and NH3 had no effect; and compounds such as galactosamine-6-PO4, 2-deoxyglucose-6-PO4, pyrophosphate, and chondrosin appeared to be inhibitory. 3. Balance studies indicated that there was little or no net disappearance of N-acetylglucosamine-6-PO4 by the enzyme system, either in the presence or absence of the substrate glucosamine-6-PO4. Using C14-uniformly labeled glucosamine-6-PO4 in the presence of normal N-acetylglucosamine-6-PO4, and isolating and counting the glucosamine-6-PO4, N-acetylglucosa-mine-6-PO4, and fructose-6-PO4 after the reaction was near to completion, showed that N-acetylglucosamine-6-PO4 was not on the carbon pathway between glucosamine-6-PO4 and fructose-6-PO4. 4. The stimulation due to the presence of N-acetylglucosamine-6-PO4 did not alter the pH optima for the reaction. 5. The inhibition of the reaction due to p-chloromercuribenzoate could not be reversed by preincubation of the enzyme with N-acetylglucosamine-6-PO4. 6. The possible mechanisms of action for this enzymic reaction based on these experimental findings are discussed.
Publication Year: 1959
Publication Date: 1959-01-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 3
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