title: Full-length and N-terminally truncated chicken intestinal diazepam-binding inhibitor. Purification, structural characterization and influence on insulin release.
abstract: Two forms of diazepam-binding inhibitor (DBI) have been purified from chicken intestine and identified as the intact avian polypeptide (residues 1-86) and a truncated variant (residues 35-86). At 10 nM concentration, both the intact and the truncated peptide suppress in vitro-monitored glucose-induced insulin release by 50 (p < 0.02) and 64% (p < 0.01) respectively. The truncation starts at a segment. -Thr-Val-Gly-Asp-, that is strictly conserved between characterized DBI species, indicating special restrictions on the structure. However, overall DBI conservation appears to be complex. A number of differently bioactive fragments with separate processings and tissue distributions have been observed, suggesting multiple functions of DBI and its sub-segments.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Z W
authors.initials: ZW
authors.lastname: Chen
authors.forename: T
authors.initials: T
authors.lastname: Bergman
authors.forename: H
authors.initials: H
authors.lastname: Jörnvall
authors.forename: V
authors.initials: V
authors.lastname: Bonetto
authors.forename: A
authors.initials: A
authors.lastname: Norberg
authors.forename: V
authors.initials: V
authors.lastname: Mutt
authors.forename: P
authors.initials: P
authors.lastname: Longone
authors.forename: E
authors.initials: E
authors.lastname: Costa
authors.forename: S
authors.initials: S
authors.lastname: Efendic
authors.forename: C G
authors.initials: CG
authors.lastname: Ostenson
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D017124:Conserved Sequence; D026261:Diazepam Binding Inhibitor; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D007329:Insulin Antagonists / Q000494:pharmacology; D007422:Intestines / Q000737:chemistry*; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017386:Sequence Homology, Amino Acid
chemical_list: D000596:Amino Acids; D002352:Carrier Proteins; D026261:Diazepam Binding Inhibitor; D007328:Insulin; D007329:Insulin Antagonists; D010446:Peptide Fragments; D005947:Glucose