SMALL PEPTIDES DERIVED FROM PENETRATIN AS ANTIBACTERIAL AGENTS

GARRO, ADRIANA; FERESIN, GABRIELA; ANDÚJAR, SEBASTIÁN; TAPIA, ALEJANDRO; PARRAVICINI, OSCAR; ENRIZ, RICARDO; LIMA, BEATRIZ; RODRÍGUEZ, ANA

San Miguel de Tucumán

Congreso; III Latin American Federation of Biophysical Societies (LAFeBS); IX IberoAmerican Congress of Biophysics; XLV Reunion Anual SAB 2016; 2016

Sociedad Argentina de Biofísica

p { margin-bottom: 0.21cm; direction: ltr; color: rgb(0, 0, 10); text-align: left; }p.western { font-family: "Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; }p.ctl { font-family: "Lohit Hindi"; font-size: 12pt; }Penetratinis a synthetic small cationic peptide possessing16 amino acids which might penetrate cell membrane. Our researchgroup was the first to report the antimicrobial activity ofpenetratin and some structurally related peptides [1-3]. We reporthere the antibacterialactivity of new peptides structurally related to penetratin and anexhaustive conformational analysis as physicochemical properties ofthese peptides may play a key role in producing their antibacterialeffects.Minimal inhibitory concentration valueswere determined using the broth microdilution method according to theprotocols of the CLSI. Conformational analysis was performed usingthe GROMACS programs package and circular dichroism spectroscopicmeasurements. Two different media (water and trifluoroethanol/water)were employed.In vitroantibacterial effects and conformational study of 13 small-sizepeptides were accomplished. These were found to be very activeantibacterial compounds, considering their small molecular size.Theoretical simulations showed that peptide helical structure isdestroyed using the matrix-mimetic environment, resulting in amixture of β-turn,bend and coil. In contrast, residues adopted a helix-likeconformation using the membrane-mimetic environment, being α-helixthe predominant form. Initial and final amino acids appear to have arandom coil structure. Analysis based on circular dichroismmeasurements were in agreement with theoretical results. Theantibacterial activity within the seriesis mainly dominated by amino acid composition adopting a definitespatial ordering. Some of these compounds are the most active smallpeptides reported until now and constitute interestingstructures for the design of new small-size peptides possessingantibacterial activity.