title: Irreversible inhibition of biotin transport in yeast by biotinyl-p-nitrophenyl ester.
abstract: Biotinyl-p-nitrophenyl ester (BNP), an active-ester derivative of biotin, irreversibly inactivates biotin transport in the yeast Saccharomyces cerevisiae. Transport inactivation is progressive with time and occurs at concentrations of the ester as low as 10(-7) M. In the presence of sodium azide, a reagent known to block biotin accumulation in yeast, the derivative is still effective. The specificity of inactivation by the ester is revealed by the following findings: (a) Biotinyl-p-nitroanilide and acetyl-p-nitrophenyl ester do not affect biotin transport; (b) the nitrophenyl ester does not affect the transport of lysine and aspartic acid, or that of L-sorbose; (c) inactivation of biotin transport by the ester is partially prevented when the cells are incubated with it in the presence of relatively high concentrations of biotin.
mesh_terms: D000596:Amino Acids; D000813:Anilides / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D001710:Biotin / Q000378:metabolism*; D002241:Carbohydrates; D004952:Esters; D009596:Nitrophenols / Q000494:pharmacology*; D012440:Saccharomyces / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D013388:Succinimides / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D000813:Anilides; D001386:Azides; D002241:Carbohydrates; D004952:Esters; D009596:Nitrophenols; D013388:Succinimides; D001710:Biotin; D012964:Sodium