CONFORMATIONAL-ANALYSIS AND HEMOLYTIC-ACT IVITY OF THE 285-292 IMMUNOGLOBULIN-G FRAGMENT AND ITS ANALOGS

Theoretical conformational analysis was carried out for the 285-292 fr agment of human immunoglobulin G (His-Asn-Ala-Lys-Thr-Lys-Pro-Arg) and its analogues containing Arg, Glu, Gly, Lys, or Trp residue istead of the His residue in position 1. Spectropolarimetric investigation of t hese peptides showed the analogues to have different activities in the C1q-mediated erythrocytes hemolysis assay. Comparison of the low-ener gy structures sets of the compounds tested allowed to suggest a model of the <<biological active>> conformation for the peptide molecule in the course of the C1q complement component binding.