Abstract
Carboxypeptidase Y from Saccharomyces cerivisiae was characterized for its site specific N-glycosylation through mass spectrometry. The N-glycopeptides were derived using non specific proteases and are analysed directly on liquid chromatography coupled to ion trap mass spectrometer in tandem mode. The evaluation of glycan fragment ions and the Y1 ions (peptide+HexNAc)+n revealed the glycan sequence and the corresponding site of attachment. We observed the microheterogeneity in N-glycans such as Man11-15GlcNAc2 at Asn13, Man8-12GlcNAc2 at Asn87, Man9-14GlcNAc2 at Asn168 and phosphorylated Man12-17GlcNAc2 as well as Man11-16GlcNAc2 at Asn368. The presence of N-glycans with Man<18GlcNAc2 indicated that in vacuoles the steady release of mannose/phospho mannose residues from glycans occurs initially at Asn13 or Asn168 followed by at Asn368. However, glycans at Asn87 which comprises Man8-12 residues as reported earlier remain intact suggesting its inaccessibility for a similar processing. This in turn indicates the interaction of the glycan at Asn87 with the polypeptide chain implicating it in the folding of the protein.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Biological Macromolecules
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
