title: Synthesis of analogs of peptides from Buthus martensii scorpion venom with potential antibiotic activity.
abstract: Five analogs of a natural peptide (BmKn1) found in the venom of scorpion Buthus martensii Karsh have been synthesized and tested to compare their antimicrobial and hemolytic activity with the wild type. Circular dichroism spectra show that these peptides form an alpha helix structure and its amino acid positions predict an amphipathic nature. Results show that increasing hydrophobicity by substituting successively positions 5 and 9 of the sequence (on the hydrophobic side of the helix) with alanine, valine and leucine enhances antimicrobial activity and hemolysis. When changes are done on positions 7 and 10 (on the hydrophilic side) by introducing more positive charges with addition of lysine, both activities also increase. However, when negative charges are introduced instead (with glutamic acids), antimicrobial activity is observed but hemolysis is reduced to zero under the concentrations studied. Although strong inhibitory activity begins at low concentrations (10μg/mL), some peptides level off inhibition and no change is observed as concentrations are increased.
authors.affiliation: Department of Chemistry, Rhodes College, 2000 North Parkway, Memphis, TN 38112, United States. Electronic address: saludbear@rhodes.edu.
authors.forename: Roberto
authors.initials: R
authors.lastname: de la Salud Bea
authors.affiliation: Department of Chemistry, Rhodes College, 2000 North Parkway, Memphis, TN 38112, United States.
authors.forename: Michael Ross
authors.initials: MR
authors.lastname: Ascuitto
authors.affiliation: Department of Biology, Rhodes College, 2000 North Parkway, Memphis, TN 38112, United States.
authors.forename: Laura Elena Luque
authors.initials: LE
authors.lastname: de Johnson
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D060829:Arthropod Proteins / Q000138:chemical synthesis / Q000494:pharmacology*; D004912:Erythrocytes / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D053878:Hemolytic Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008826:Microbial Sensitivity Tests; D017433:Protein Structure, Secondary; D012604:Scorpion Venoms / Q000737:chemistry; D012605:Scorpions
chemical_list: D000900:Anti-Bacterial Agents; D060829:Arthropod Proteins; D053878:Hemolytic Agents; D012604:Scorpion Venoms
keywords: Alpha-helix; Amphipathic; Antimicrobial peptides; Hemolysis