title: Structural and charge requirements for antimicrobial and hemolytic activity in the peptide PKLLETFLSKWIG, corresponding to the hydrophobic region of the antimicrobial protein bovine seminalplasmin.
abstract: Several analogs of the 13-residue antimicrobial and hemolytic peptide PKLLETFLSKWIG (SPF), which is the most hydrophobic region of the 47-residue antimicrobial protein seminalplasmin [Sitaram, N. & Nagaraj, R. (1990) J. Biol. Chem. 265, 10438-10442] have been synthesized. The antimicrobial and hemolytic properties of the peptides were investigated with a view to gain a insight into the structural and charge requirements for these activities of SPF. Peptides in which E was replaced by K exhibited considerably improved antimicrobial activity with no concomitant increase in hemolytic activity. A peptide in which the aromatic amino acids were replaced by leucine exhibited antimicrobial activity like those of the peptides which had aromatic amino acids. Interchange in the positions of E and K and total replacement of K by E resulted in complete loss of activity. The peptides having antimicrobial activity like those of the peptides which had aromatic amino acids. Interchange in the positions of E and K and total replacement of K by E resulted in complete loss activity. The peptides having antimicrobial activities showed appreciable helical content in a hydrophobic environment, whereas inactive peptides did not. Thus, by suitable 'engineering' the biological activity of a short 13-residue peptide can be altered by yield peptides specifically having only antimicrobial activity with increased potency.
authors.affiliation: Centre for Cellular and Molecular Biology, Hyderabad, India.
authors.forename: N
authors.initials: N
authors.lastname: Sitaram
authors.forename: C
authors.initials: C
authors.lastname: Subbalakshmi
authors.forename: R
authors.initials: R
authors.lastname: Nagaraj
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002417:Cattle; D015941:Complement Hemolytic Activity Assay; D006461:Hemolysis; D008297:Male; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D015202:Protein Engineering; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D012661:Semen / Q000378:metabolism; D029607:Seminal Vesicle Secretory Proteins; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D010446:Peptide Fragments; D010743:Phospholipids; D011506:Proteins; D029607:Seminal Vesicle Secretory Proteins