Conformational Analysis of Linear Peptide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7NH_2 )

Authors: LÜTFÜ DEMİR, ABDULHALİK KARABULUT, GÖKHAN BUDAK, YUSUF ŞAHİN, NAGIF SEFTEROĞLU

Abstract: Conformational energy-minimization of the Sea Anemone and Sea Pansy neuropeptide Pol-RFamide (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7-NH_2) was carried out by molecular mechanics (MM). The linkage bonds were characterized by the torsion angles \theta, \psi and \omega and the side groups were characterized by the torsion angles \chi_1, \chi_2, \chi_3\ldots The energy-map for each monopeptide of the Pol-RFamide I was drawn in the range of -180° to 180° with increments of 20°. Conformation facilities for monopeptides were determined from these maps. These results were used in the analysis of the dipeptide (Glu^1-Leu^2). Then, the (Glu^1-Leu^2-Leu^3) tripeptide was examined using the calculated results for the dipeptide. Conformational analysis of the (Glu^1-Leu^2-Leu^3-Gly^4) tetrapeptide was performed using the low-energy values for the tripeptide. The space structure of the (Glu^1-Leu^2-Leu^3-Gly^4-Gly^5-Arg^6-Phe^7-NH_2) neuropeptide was found as a result of minimization of energies by rotating the tetrapeptide (Glu^1-Leu^2-Leu^3-Gly^4) and the dipeptide (Arg^6-Phe^7-NH_2) about the monopeptide (Gly^5).

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