title: Preparation and properties of covalently linked insulin dimers.
abstract: The synthesis of six isomeric insulin dimers, linked through selected amino groups of the monomers by a dicarboxylic acid, is described. Symmetrical dimers were obtained by direct crosslinking of N,N-bis(methylsulfonyl-ethoxycarbonyl)insulins with the bis(p-nitrophenyl) esters of dicarboxylic acids. The synthesis of asymmetrical dimers was achieved by use of Msc-protected insulin active ester intermediates. N epsilon-B29,N epsilon B29'-Insulin dimers containing oxalyl, suberoyl and dodecanedioyl crosslinks were produced. N alpha B1,N epsilon B29'-Insulin dimers were suberoyl and dodecanedioyl crosslinks were synthesized; all other dimers were synthesized with suberoyl crosslinks. The positions of crosslinks were determined by sulfitolysis, tryptic digestion, electrophoresis and quantitative end-group determination. The dimers showed potencies between 1-60% that of insulin on a weight basis in stimulating lipogenesis in isolated fat cells. The potencies are considerably lower than the relative binding affinities determined with isolated fat cells.
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001681:Biological Assay; D002417:Cattle; D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D007328:Insulin / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D008055:Lipids / Q000096:biosynthesis; D008099:Liver / Q000378:metabolism; D008722:Methods; D051379:Mice; D051381:Rats; D011972:Receptor, Insulin / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D007202:Indicators and Reagents; D007328:Insulin; D008055:Lipids; C034329:insulin dimers; D011972:Receptor, Insulin