PMID:391265
| Citation |
Wong, YH, Winer, FB and Frey, PA (1979) p-(Bromoacetamido)phenyl uridyl pyrophosphate: an active-site-directed irreversible inhibitor for uridine diphosphate galactose 4-epimerase. Biochemistry 18:5332-6 |
|---|---|
| Abstract |
The synthesis of p-(bromoacetamido)phenyl uridyl pyrophosphate (BUP) is described. This compound is an active-site-directed irreversible inhibitor of Escherichia coli UDP-galactose 4-epimerase. The inactivation follows pseudo-first-order kinetics at pH 8.5 in nonnucleophilic buffers, and a saturation effect is seen in the pseudo-first-order rate constant as the concentration of BUP is increased. The half-saturation parameter for BUP in the inactivation is 0.21 +/- 0.02 mM, which compares favorably with the inhibition constant of 0.3 +/- 0.05 mM for BUP acting as a competitive reversible inhibitor of the enzyme. The inactivation rate is slow, however, with a minimum half-time of 12 h at pH 8.5 and 27 degrees C. Both specific alkylation and nonspecific alkylation by BUP occur, but nonspecific alkylation is faster than the inactivation and the rate of inactivation correlates well with the rate of covalent incorporation of one molecule of [14C]BUP at the active site. |
| Links | |
| Keywords |
Binding Sites; Carbohydrate Epimerases/antagonists & inhibitors; Carbon Radioisotopes; Escherichia coli/enzymology; Kinetics; Protein Binding; Spectrophotometry, Ultraviolet; UDPglucose 4-Epimerase/antagonists & inhibitors; Uracil Nucleotides/analogs & derivatives; Uridine Diphosphate/analogs & derivatives |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.