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Y 2 receptor proteins for peptide YY and neuropeptide Y Characterization as N ‐linked complex glycoproteins
Author(s) -
Hansen Anette P.,
Sheikh Søren P.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80987-r
Subject(s) - neuraminidase , sialic acid , chemistry , glycoprotein , pngase f , biochemistry , receptor , oligosaccharide , molecular mass , endoglycosidase , peptide , enzyme , endoglycosidase h , glycan , endoplasmic reticulum , golgi apparatus
Affinity labeling using [ 125 I‐Tyr 36 ]PYY and homobifunctional affinity crosslinking reagents of the rabbit Y 2 receptor for peptide YY(PYY) results in specifically labeled proteins of both M r =50,000 to 60,000 and M r =96,000 to 115,000 [1,2]. In this work the glycoprotoin nature of affinity labeled Y 2 receptor proteins were investigated by enzymatic deglycosylation using neuraminidase, endoglycosidase F (endo F), N ‐glycosidase F (PNGase F), and O ‐glycanase treatment. Only N ‐glycosidase F and neuraminidase increased the electrophoretic mobility of the radiolabeled receptor bands, whereas all other glycosidases did not. PNGase F treatment of both radiolabeled receptor bands electroeluted from gel slices reduced the apparent molecular mass of by 16–17 kDa units, that is M r =96,000 to 79,000 and M r =60,000 to 44,000, indicating removal of N ‐linked oligosaccharide chains of similar size from both species. Neuraminidase treatment caused slight increases in the electrophoretic mobilities suggesting the presence of terminal sialic residues. It is concluded that the Y 2 binding proteins are N ‐linked complex (sialo)glycoproteins with a minimal core protein size of M r =44,000. Furthermore, based on this sensitivity pattern of the glycosidases, the Asn‐linked carbohydrate may be of the tri‐ or tetra‐antennary complex type containing terminal sialic acid residues.