Conservative and variable regions of homologous snake phospholipases A2 sequences: prediction of the taxon-specific peptides structure.

Homologous amino acid sequences of phospholipases A2 (PLA2) of snakes belonging to the families Elapidae, Viperidae, and Colubridae were considered in order to study the conservative and variable regions location. The PLA2 sequences were divided into two groups (taxons) according to the phylogenetic tree reconstructed from the pair similarity matrix. Results of the intergroup comparison were plotted to facilitate the identification of significant conservative and variable regions. It was shown that the results of the comparison between two phylogenetic groups of snake PLA2 did not much depend on the number of each group representatives and did not markedly change if one of the groups was represented by the single sequence. The knowledge of the number and location of conservative and variable regions and their dependence on the phylogenetic relations between compared taxa may be used to predict a synthetic peptide structure to obtain specific antibodies against PLA2 of one of these taxons. Such prediction is possible if there is a specific region conservative for one taxon but variable for two of them.