title: Structure, antihyperglycemic activity and cellular actions of a novel diglycated human insulin.
abstract: Human insulin was glycated under hyperglycemic reducing conditions and a novel diglycated form (M(r) 6135.1 Da) was purified by RP-HPLC. Endoproteinase Glu-C digestion combined with mass spectrometry and automated Edman degradation localized glycation to Gly(1) and Phe(1) of the insulin A- and B-chains, respectively. Intraperitoneal (i.p.) administration of diglycated insulin to mice alone or in combination with glucose (7 nmol/kg) resulted in a 43-61% and 11-34% reduction in glucose lowering activity, respectively, compared with native insulin. Consistent with these findings, diglycated insulin (10(-9) to 10(-7) mol/liter) was 22-38% less effective (P < 0.001) than native insulin in stimulating glucose uptake, glucose oxidation and glycogen production in isolated mouse abdominal muscle.
authors.affiliation: School of Biomedical Sciences, University of Ulster, BT52 1SA, Northern, Coleraine, Ireland. fpm.oharte@ulst.ac.uk
authors.forename: F P
authors.initials: FP
authors.lastname: O'Harte
authors.forename: A C
authors.initials: AC
authors.lastname: Boyd
authors.forename: A M
authors.initials: AM
authors.lastname: McKillop
authors.forename: Y H
authors.initials: YH
authors.lastname: Abdel-Wahab
authors.forename: H
authors.initials: H
authors.lastname: McNulty
authors.forename: C R
authors.initials: CR
authors.lastname: Barnett
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
authors.forename: P
authors.initials: P
authors.lastname: Højrup
authors.forename: P R
authors.initials: PR
authors.lastname: Flatt
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003847:Deoxyglucose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D006003:Glycogen / Q000096:biosynthesis; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D006031:Glycosylation; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D007274:Injections, Intraperitoneal; D007328:Insulin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008815:Mice, Inbred Strains; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D006023:Glycoproteins; D007328:Insulin; D006003:Glycogen; D003847:Deoxyglucose; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D005947:Glucose