A stable analogue has been prepared of the enediolate anion believed to occur transiently in the reaction of phosphoglucose isomerase. This compound, 5 phosphoarabinonate, is the strongest known competitive inhibitor of the enzyme (K(i) = 3 x 10-7M below pH 7). A distinctive pH dependence of binding, also found for two other aldonic acid ω phosphates, 6 phosphogluconate and 4 phosphoerythronate, involves perturbation of a pKa from 7.0 in the free enzyme to 9.0 in the enzyme inhibitor complex. This perturbation may reflect a catalytically advantageous increase in basicity which occurs around the transition state of the normal enzymatic reaction.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Biological Chemistry|
|State||Published - Dec 1 1975|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology