Mini-Symposium - Abstracts
13 MOLECULAR EVOLUTION OF PHOSPHOLIPASES A2 FROM VENOMS OF VIPERS
A.M. MOURA-DA-SILVA
, R.D.G. THEAKSTON
, J.M. CRAMPTON
Laboratory of Immunopathology, Butantan Institute, São Paulo, Brazil, Venom Research and Molecular Genetic Units, Liverpool School of Tropical Medicine, Liverpool, UK.
The study of the evolutionary mechanisms of protein families present in snake venoms may be considered as one more approach in understanding the structure/function relationships of venom toxins. This study was carried out by analyzing 29 amino acid sequences of venom group II PLA2s and also 12 cDNA sequences cloned in our laboratory or retrieved from the data banks. The alignment of the cDNA sequences showed the greatest sequence variation occurring in the region coding for the mature protein, mostly with non-synonymous substitutions. The phylogenetic tree constructed by the alignment of the amino acid sequences generally groups them according to the functional activity, not always respecting the current taxonomical divisions of the snake. It also suggests that gene duplications may have occurred at a number of different points during the evolution of this protein family. The gene duplication followed by hypervariability of the amino acids in the functional domains and positive selection may have assisted the generation of the functional diversity of venom group II PLA2s.
Financial support: CNPq (Brazil) and the Wellcome Trust (UK).
CORRESPONDENCE TO:
Dra. Ana Maria Moura da Silva - Instituto Butantan, Laboratório de Imunopatologia, Avenida Vital Brazil, 1500, CEP 05503-900, São Paulo, SP, Brasil. email: anamoura@usp.br
Publication Dates
-
Publication in this collection
08 Jan 1999 -
Date of issue
1997
