Conformational study of linear and cyclic peptides corresponding to the 276-284 epitope region of HSV gD-1

The results of conformational analysis of linear and cyclic peptides from the 276SALLEDPVG(284) sequence of glycoprotein D of Herpes simplex virus are presented. The epitope peptides were synthesized by SPPS and on resin cyclization was applied for preparation of cyclic compounds. Circular dichroism spectroscopy, Fourier-transform infrared spectroscopy and nuclear magnetic resonance (NMR) were used to determine of the solution structure of both linear and cyclic peptides. The results indicated that the cyclopeptides containing the core of the epitope (DPVG) as a part of the cycle have more stable beta-turn structure than the linear peptides or the cyclic analogues, where the core motif is not a part of the cycle. NMR study of H-SALLc(EDPVGK)-NH(2) confirm presence of a type I beta-turn structure which includes the DPVG epitope core.