Tyrosine-glycogen obtained from retina proteoglycogen by exhaustive proteolytic digestion was radiolabelled with 125I. The 125I-labelled tyrosine-glycogen was degraded by amylolytic digestion to a very small radioactive product, which was identified as iodotyrosine by h.p.l.c. The amylolytic mixture used released glucose and maltose that were alpha-linked to the phenolic hydroxy group of p-nitrophenol. No free iodotyrosine was found before or after the intact [125I]iodotyrosine-glycogen was subjected to two cycles of the Edman degradation procedure. The linkage between protein and glycogen was alkali-stable. Therefore it is concluded that the protein-bound glycogen was O-glycosidically linked to the phenolic hydroxy group of tyrosine. The amino acid has not been heretofore found to be involved in the linkage of carbohydrates to proteins.
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Research Article| July 01 1985
Protein-bound glycogen is linked to tyrosine residues
Biochem J (1985) 229 (1): 269–272.
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M A Aon, J A Curtino; Protein-bound glycogen is linked to tyrosine residues. Biochem J 1 July 1985; 229 (1): 269–272. doi: https://doi.org/10.1042/bj2290269
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