Use of a phosphopeptide as a ligand to purify phospholipase A2 from the venom of Crotalus durisuss terrificus by affinity chromatography. Soledad L.Saavedra, GerardoAcosta, LucíaÁvila, Silvana L.Giudicess.Silvia A.Camperi, FernandoAlbericio, OsvaldoCascone, María C.Martínez Ceron. Journal of Chromatography B. In Press