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Metabolic labelling and partial characterization of glycophospholipids in pancreatic islet cells
Author(s) -
Albor Amador,
Cáamara Javier,
Mato José M.,
Malaisse Willy J.,
Verde Isabel Val
Publication year - 1991
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.290090202
Subject(s) - labelling , islet , chemistry , biochemistry , microbiology and biotechnology , biology , endocrinology , insulin
Insulin action is thought to be mediated by an inositol‐, glucosamine‐ and galactose‐containing oligosaccharide liberated by phosphodiesterase hydrolysis of a glycosyl‐phosphatidylinositol. This oligosaccharide inhibits insulin biosynthesis and secretion in pancreatic islets. In the present study, two main glycolipids (peak I and II) were resolved by sequential TLC of lipids extracted from islet cells labelled with tritiated glucosamine, galactose or myristate. The two glycolipids displayed comparable sensitivity to β‐galactosidase but differed from one another by their sensitivity to phosphatidylinositol‐specific phospholipase C. Moreover, structural heterogeneity within each peak was suggested by their partial resistance to nitrous acid deamination. These findings support the presence in islet cells of glycolipids similar to those currently considered as a possible postreceptor target for insulin in other cell types.