VARIABILITY ANALYSIS OF HIV-1 GP120 V3 REGION - III - DISTINCTIONS BETWEEN VARIOUS SETS OF PEPTIDE-FRAGMENTS DERIVED FROM THE SEQUENCES BELONGING TO DIFFERENT HIV-1 TAXONS

Distinction criterion for various sets of fixed length peptide fragmen ts and integral distinction measure for various sets of peptide fragme nts with different length and start position ranges have been introduc ed on the base of an enumeration procedure and a point estimators for the amino acid distribution characteristics introduced previously (M. Yu. Shchelkanov, A. N. Yudin, A. V. Antonov, N. S. Starikov, A. A. Ved enov, E. V. Karamov, J. Biomol. Struct. Dyn. 15, 231-241 (1997)). Diff erences between 6-10-mer peptides derived from the majority of HN-I ta xon pairs are demonstrated to be located generally in the vicinity of the V3-loop top. This validates the suitability of V3 top mimicking sy nthetic peptides for HIV-1 serotyping. A significant difference betwee n E subtype V3 C-terminus peptides and the corresponding peptides deri ved from the other subtypes has been demonstrated. Taking into account the Langerhans' cells tropism of E subtype virus variants we have hyp othesized the influence of mutations in the V3 C-terminus on HIV-1 cel l tropism.