| Research Abstract |
Recently, we reported the amino acid sequence of chicken α_1-acid glycoprotein(chicken α_1-AGP)(Biochem.Biophys.Res.Commun.295(2002)587-590). In this study, we identify disulfide bonds and site-specific glycosylation in chicken α_1-AGP using tryptic digests of carbamidomethylated, chicken α_1-AGP, carbamidomethylated, completely deglycosylated chicken α_1-AGP(cd-α_1-AGP), and non-reduced, denatured cd-α_1-AGP by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS). Based on the existence of the peptides detected at m/z 3037.4(amino acid sequence 69-76 plus 161-183) and 3453.3(amino acid sequence 69-80 plus 161-183), the location of two disulfide bonds of chicken α_1-AGP was determined to be Cys 6-Cys 146 and Cys 73-Cys 163. Furthermore, it was found that Asn 16,70,77 and 87 were fully glycosylated, and that Asn 62 was partially glycosylated.
|
