This work is aimed at synthesizing three analogs of the natural peptaibol antibiotic trichogin GA IV, containing the H-L-pCN-(αMe)Phe-OH residue: n-oct-Aib-Gly-L-Leu-L-pCN-(αMe)Phe-Gly-Gly-L-Leu-Aib-Gly-L-Ile-L-Lol (1) n-oct-Aib-Gly-L-Leu-Aib-Gly-Gly-L-Leu-L-pCN-(αMe)Phe-Gly-L-Ile-L-Lol (2) n-oct-L-pCN-(αMe)Phe-Gly-L-Leu-Aib-Gly-Gly-L-Leu-Aib-Gly-L-Ile-L-Lol (3) The pCN-phenyl moiety is a spectroscopic probe (IR and fluorescence) that will be helpful to study the interaction mechanism between peptaibols and lipidic membranes. The peptide 3 has been synthesized on solid phase, while the segments of peptides 1 and 2 have been prepared in solution. The conformational studies (IR, NMR and CD) performed in solution demonstrate that the synthesized peptides fold into stable helical conformations. Studies with model membranes have shown that peptide 3 has a significant tendency to permeate the phospholipid double layer. Moreover, we have observed that also the pCN-phenyl group of pCN-(αMe)Phe is sensitive to the surrounding. Indeed, the CN stretching undergoes a noticeable shift in the IR spectral region (2225-2231 cm-1), depending upon the solvent. Thus, this group is a worthy probe to investigate the interaction mechanism between trichogin and lipidic membranes.

Sintesi, caratterizzazione e studi conformazionali di analoghi dell'antibiotico peptidico tricogina GA IV, contenenti l'amminoacido pCN-(alfaMe)Phe

Longo, Edoardo
2009/2010

Abstract

This work is aimed at synthesizing three analogs of the natural peptaibol antibiotic trichogin GA IV, containing the H-L-pCN-(αMe)Phe-OH residue: n-oct-Aib-Gly-L-Leu-L-pCN-(αMe)Phe-Gly-Gly-L-Leu-Aib-Gly-L-Ile-L-Lol (1) n-oct-Aib-Gly-L-Leu-Aib-Gly-Gly-L-Leu-L-pCN-(αMe)Phe-Gly-L-Ile-L-Lol (2) n-oct-L-pCN-(αMe)Phe-Gly-L-Leu-Aib-Gly-Gly-L-Leu-Aib-Gly-L-Ile-L-Lol (3) The pCN-phenyl moiety is a spectroscopic probe (IR and fluorescence) that will be helpful to study the interaction mechanism between peptaibols and lipidic membranes. The peptide 3 has been synthesized on solid phase, while the segments of peptides 1 and 2 have been prepared in solution. The conformational studies (IR, NMR and CD) performed in solution demonstrate that the synthesized peptides fold into stable helical conformations. Studies with model membranes have shown that peptide 3 has a significant tendency to permeate the phospholipid double layer. Moreover, we have observed that also the pCN-phenyl group of pCN-(αMe)Phe is sensitive to the surrounding. Indeed, the CN stretching undergoes a noticeable shift in the IR spectral region (2225-2231 cm-1), depending upon the solvent. Thus, this group is a worthy probe to investigate the interaction mechanism between trichogin and lipidic membranes.
2009-10
84
Trigogine, antibiotici, peptaibolici, pCN-Phe
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12608/12643