Biopolymers and cell. 1992. Volume 8. № 4. 20 - 30

POYARKOVA S. A., KUKHAR V. P., KOLICHEVA M. T., HRAPUNOV S. N., DRAGAN A. I.

Dipeptides Conteining m- and p-Fluorophenylalanine. Synthesis Separation on Optical Isomers and Study of Their Substrate Properties Towards Thrombin

Summary

    In order to search of new substrates and inhibitors for thrombin DL-and LL-stereoisomers of dipeptide Tos-Phe-(X)-Arg-OCH3 (where X-tn- or p-fluorophe-uylalanine) were synthesized by classical methods of peptide chemistry from racemate tosylfluorophenylalanine. Tos-L-Phe(pF)-Arg-OCH3 showed substrate's activation at con¬centration [S] >KH and inhibition by substrate at [S] < Kn. Tos-L-Phe(mF)-Arg-OCH3 has no bioregulatory effect. Isomers containing £)-fluorophenylalanine are not split by thrombin. Study of absorption spectrum and difference in spectrums of fluorescence sho¬wed different conformational flexibility of DL and LL isomers. Bathochromic shift in ab¬sorption spectrum and fluorescent spectrums of m-fluorophenylalanine is differ from the same of dipeptide, containing p-fluorophenylalanine. The connection between conforma¬tional flexibility and substrate's properties of dipeptides is discussed.