Isolation of three antibacterial peptides from pig intestine: gastric inhibitory polypeptide (7-42), diazepam-binding inhibitor (32-86) and a novel factor, peptide 3910.
Two antibacterial peptides, cecropin P1 and PR-39 (39-residue proline/arginine-rich peptide), from the upper part of pig small intestine have previously been isolated and characterized. We have now continued our search for antibacterial peptides in different side fractions generated during the isolation of intestinal hormones. Starting from one such fraction and monitoring activity against Bacillus megaterium, we isolated three homogeneous peptides by three consecutive chromatographic steps. Amino acid sequence analysis in combination with mass spectrometry identified two of the peptides as gastric inhibitory polypeptide (7-42) [GIP(7-42)] and diazepam-binding inhibitor (32-86) [DBI(32-86)], derived from factors already known. However, intact GIP and DBI have hardly any antibacterial activity by themselves. The third peptide constitutes a previously unknown structure, designated as peptide 3910 from its molecular mass. All three peptides showed good activity against B. megaterium. In addition, GIP (7-42) showed some activity against Streptococcus pyogenes and an Escherichia coli mutant with a defect in its outer membrane.
Department of Biochemistry II, Karolinska Institutet, Stockholm, Sweden.
B
B
Agerberth
A
A
Boman
M
M
Andersson
H
H
Jörnvall
V
V
Mutt
H G
HG
Boman
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001410:Bacillus megaterium / Q000187:drug effects; D020789:Cathepsin C; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects; D005749:Gastric Inhibitory Polypeptide / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005768:Gastrointestinal Hormones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007421:Intestine, Small / Q000737:chemistry*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013297:Streptococcus pyogenes / Q000187:drug effects; D013552:Swine
D000900:Anti-Bacterial Agents; D005768:Gastrointestinal Hormones; D009479:Neuropeptides; D010446:Peptide Fragments; C083244:diazepam-binding inhibitor (32-86); C083243:gastric inhibitory polypeptide (7-42); C083245:peptide 3910; D005749:Gastric Inhibitory Polypeptide; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D020789:Cathepsin C