Derivatization of phosphopeptides with mercapto- and amino-functionalized conjugate groups by phosphate elimination and subsequent Michael addition

Organic & Biomolecular Chemistry Pub Date: 2005-07-13 DOI: 10.1039/B505573C

Abstract

Kinetics of the β-elimination of the phosphate group from H–Tyr–Ser(PO3H2)–Phe–OH and H–Tyr–Thr(PO3H2)–Phe–OH and subsequent addition of thiols and amines to the dehydroalaninyl and β-methyldehydroalaninyl residues formed, were followed by RP HPLC under alkaline conditions in the absence and presence of Ba2+ ions. By this reaction sequence, the phosphoserinyl peptide was conjugated with mono-N-(2-mercaptoethyl)amide of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (4), a mercapto-functionalized pentapeptide, H–His–Gly–Gly–His–Gly–NH(CH2)4SH, and an amino-functionalized fluorescent dye, 5-dimethylaminonaphthalene-1-[N-(5-aminopentyl)]sulfonamide (dansyl cadaverine). The β-methyldehydroalanine residue was, in turn, observed to be a poor Michael acceptor.

Graphical abstract: Derivatization of phosphopeptides with mercapto- and amino-functionalized conjugate groups by phosphate elimination and subsequent Michael addition
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