Open AccessCarbohydrate structures of acetylcholine receptor from Torpedo californica and distribution of oligosaccharides among the subunits
Author(s) -
NOMOTO Hiroshi,
TAKAHASHI Noriko,
NAGAKI Yasuhiro,
ENDO Satoshi,
ARATA Yoji,
HAYASHI Kyozo
Publication year - 1986
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1986.tb09661.x
Subject(s) - oligosaccharide , torpedo , concanavalin a , chemistry , biochemistry , glycoconjugate , lectin , wheat germ agglutinin , carbohydrate , acetylcholine receptor , mannose , glycan , carbohydrate conformation , receptor , agglutinin , glycoprotein , polysaccharide , in vitro
The structure of carbohydrates in acetylcholine receptor (AChR) from Torpedo californica is reported. Oligosaccharides released quantitatively from the whole molecule by N ‐oligosaccharide glycopeptidase digestion were fractionated by thin‐layer chromatography and further purified by high‐performance liquid chromatography. We show that more than 70% of the total oligosaccharide chains in Torpedo AChR are of the high‐mannose type with the structures (Man) 8 (GlcNAc) 2 and (Man) 9 (GlcNAc) 2 . The structure of these oligosaccharides were determined by proton nuclear magnetic resonance spectroscopy. These two types of oligosaccharides were shown to be distributed in different proportions in all subunits of Torpedo AChR. We also show that several kinds of complex‐type oligosaccharides comprising the rest of the carbohydrate in the protein exist mainly in the γ and δ subunits. The structure of the carbohydrate moiety that is distributed on the four subunits of AChR was also examined by susceptibility to endo‐β‐ N ‐acetylglucosaminidase and sialidase and by binding affinity to lectins, e.g. concanavalin A, leucoagglutinating phytohemagglutinin, and wheat germ agglutinin.