| 主权项 |
1. A method of labeling a sulfenic acid (—SOH) group of a cysteine residue in a protein or peptide, comprising:
(a) contacting said protein or peptide with a beta-ketoester to covalently couple said beta-ketoester to said cysteine residue and form a beta-ketoester-labeled cysteine residue in said protein or peptide; and then (b), cleaving said beta-ketoester-labeled cysteine residue to produce a 5-isoxazolone-labeled cysteine residue in said protein or peptide; wherein said beta-ketoester is a compound of Formula I:wherein:
X is H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkenyl, cycloalkylalkynyl, heterocyclo, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, heteroaryl, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, alkoxy, halo, mercapto, azido, cyano, formyl, carboxylic acid, hydroxyl, nitro, acyl, aryloxy, alkylthio, amino, alkylamino, arylalkylamino, disubstituted amino, acylamino, acyloxy, ester, amide, sulfoxyl, sulfonyl, sulfonate, sulfonic acid, sulfonamide, urea, alkoxylacylamino, aminoacyloxy, or a detectable group; Y is a covalent bond or an alkylene croup or a linker; and Z is alkynyl. |
