title: Temporin A and its retro-analogues: synthesis, conformational analysis and antimicrobial activities.
abstract: Temporin A (TA) is a hydrophobic peptide isolated from the skin of the European red frog Rana temporaria. Strong antimicrobial activity against gram-positive cocci and Candida, as well as its small molecular weight (10-13 aa residues), makes TA an interesting antimicrobial compound. However, its synthesis is rather problematic. Here, the synthesis of two retro-analogues of TA--retro-TA and (6-1)(7-13)-TA--is reported. The synthesis of retro-TA was performed without any problems, while during the synthesis of (6-1)(7-13)-TA problems similar to those encountered during the synthesis of TA were faced. Antimicrobial assays showed minimal inhibitory concentration (MIC) values of retro-TA to be, in most cases, only one dilution higher than those of original TA, but still remained relatively low. An analysis of the circular dichroism spectra of the peptides shows that TA and (6-1)(7-13)-TA adopt an alpha-helical structure in a hydrophobic environment, while retro-TA forms mainly unordered conformation under both hydrophobic and hydrophilic conditions. One can postulate that differences in conformation of the peptide chain might be responsible for the lower antimicrobial activity of retro-TA as compared to that of the parent molecule. In any case, retro-TA can be interesting owing to its simple and nonproblematic synthesis.
authors.affiliation: Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Sobieskiego 18, 80-952 Gdańsk, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Kamysz
authors.forename: Beata
authors.initials: B
authors.lastname: Mickiewicz
authors.forename: Sylwia
authors.initials: S
authors.lastname: Rodziewicz-Motowidło
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Greber
authors.forename: Marcin
authors.initials: M
authors.lastname: Okrój
mesh_terms: D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D001419:Bacteria / Q000187:drug effects; D002942:Circular Dichroism / Q000379:methods; D008826:Microbial Sensitivity Tests / Q000379:methods; D011487:Protein Conformation; D011506:Proteins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D011506:Proteins; C104501:temporin