title: Porcine pulmonary surfactant preparations contain the antibacterial peptide prophenin and a C-terminal 18-residue fragment thereof.
abstract: Surfactant preparations obtained from porcine lungs by extraction with chloroform/methanol followed by chromatography over Lipidex-5000 are used for treatment of respiratory distress syndrome in preterm infants. These preparations contain about 98% phospholipids and 1-2% of the hydrophobic pulmonary surfactant-associated proteins B and C (SP-B and SP-C). Separation of the proteins in the surfactant preparation by reversed-phase high performance liquid chromatography revealed, in addition to SP-B and SP-C, the presence of three peptides derived from the cathelicidin family of antibacterial peptides. The 79-residue proline-rich peptide prophenin (identical to that isolated from leukocytes), an 80-residue prophenin with an N-terminal pyroglutamic acid residue, and a C-terminal 18-residue fragment of prophenin were found in approximate molar ratios of 1:20:5. A synthetic version of the C-terminal 18-residue peptide exhibits salt-dependent antibacterial activity (higher activity in the absence of salt) against the Gram-positive bacterium Bacillus megaterium Bm11 and, to a lesser extent, against Gram-negative Escherichia coli D21 cells. It appears possible that the presence of prophenin peptides may contribute to the antibacterial properties of surfactant preparations.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77, Stockholm, Sweden.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: W J
authors.initials: WJ
authors.lastname: Griffiths
authors.forename: T
authors.initials: T
authors.lastname: Curstedt
authors.forename: J
authors.initials: J
authors.lastname: Johansson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000032:analysis*; D023181:Antimicrobial Cationic Peptides; D002851:Chromatography, High Pressure Liquid; D008168:Lung / Q000378:metabolism; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000032:analysis; D013552:Swine; D013997:Time Factors; D054804:Cathelicidins
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D010455:Peptides; D011506:Proteins; D011663:Pulmonary Surfactants; D011761:Pyrrolidonecarboxylic Acid; C092764:prophenin 1; C084994:NPG4 protein, Sus scrofa; D054804:Cathelicidins