Derivatization of phosphopeptides with mercapto- and amino-functionalized conjugate groups by phosphate elimination and subsequent Michael addition.
Kinetics of the beta-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 beta-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 beta-methyldehydroalanine residue was, in turn, observed to be a poor Michael acceptor.
Mattila
Kati
K
Department of Chemistry, University of Turku, FIN-20014, Turku, Finland.
Siltainsuu
Jaana
J
Balaspiri
Lajos
L
Ora
Mikko
M
Lönnberg
Harri
H
D000588:Amines / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010748:Phosphopeptides / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry
D000588:Amines; D010710:Phosphates; D010748:Phosphopeptides; D013438:Sulfhydryl Compounds