N-Glycosylation analysis of yeast Carboxypeptidase Y reveals the ultimate removal of phosphate from glycans at Asn(368)

Kumar, B S Gnanesh and Surolia, Avadhesha (2017) N-Glycosylation analysis of yeast Carboxypeptidase Y reveals the ultimate removal of phosphate from glycans at Asn(368). In: INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, 98 . pp. 582-585.

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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 Y-1 ions (peptide + HexNAc)(+n) revealed the glycan sequence and the corresponding site of attachment. We observed the microheterogeneity in N-glycans such as Man(11-15)GIcNAc(2) at Asn(13), Man(8-12)GIcNAc(2) at Asn(87), Man(9-14)GIcNAc(2) at Asn(168) and phosphorylated Man(12_17)GIcNAc(2) as well as Man(11)_(16)G1cNAc(2) at Asn(368). The presence of N-glycans with Man(<18)GIcNAc(2) 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 Man(8-12) 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. (C) 2017 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	20 May 2017 04:14
Last Modified:	20 May 2017 04:14
URI:	http://eprints.iisc.ac.in/id/eprint/56839

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