Fluorogenic substrates for BETA-lactamase gene expression

Abstract

Fluorescent substrates for beta-lactamases having the general formula shown above are provided. Z includes a fluorophore or chromophore and includes a group that may link to the lactam-containing group; R1 and R2 are independently selected from H, aliphatic, aromatic, alkyl, and acyl; R4 may be H and lower alkyl; B may be H, physiologically acceptable salts or metal, ester groups, ammonium cations, —CHR5OCO(CH2)nCH3, —CHR5OCOC(CH3)3, acylthiomethyl, acyloxy-alpha-benz, deltabutyrolactonyl, methoxycarbonyloxymethyl, phenyl, methylsulphinylmethyl, beta-morpholinoethyl, dialkylaminoethyl, and dialkylaminocarbonyloxymethyl, in which R5 is selected from the group consisting of H and lower alkyl; n is an integer between 0 and 10, inclusive; and A may be S, O, SO, SO2 or CH2. In embodiments, the beta-lactam ring may be cleaved by a beta-lactamase enzyme effective to free a fluorophore. Methods of assaying beta-lactamase activity and monitoring expression in systems using beta-lactamase as a reporter gene are also disclosed.

Dependencies are inferred from the claim text.