Equine antibodies to Bothrops asper myotoxin II: isolation from polyvalent antivenom and neutralizing ability.

Equine antibodies to B. riper myotoxin II were isolated from polyvalent antivenom by affinity chromatography. Purified antibodies were among the most acidic serum immunoglobulins, migrating between the ß- and aZ-globulin regions by zone electrophoresis . This might be related to the fact that myotoxin II is a very basic antigen. At an antibody/toxin molar ratio of two or higher, myotoxic effect of myotoxin II was neutralized completely . Antibodies also neutralized myotoxic activity of crude venom in mice, reducing the effect by about 75% when a proportion of 16 mg antibodies/mg venom was tested . Despite the lack of phospholipase AZ activity of myotoxin II, antibodies were able to neutralize this enzymatic activity of myotoxin I, a previously described isoform. This finding is in agreement with the notion that myotoxin II is a phospholipase AZ-analog devoid of this enzyme activity.Vicerrectoria de Investigación, Universidad de Costa Rica/[No. 741-88-009]/UCR/Costa RicaInternational Foundation for Science/[No. F/1388-1]/IFS/SwedenOrganización de las Naciones Unidas para la Educación, la Ciencia y la Cultura/[No. 1041-R]/UNESCO/Costa Rican National Scientific and Technological Research Council//CONICIT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP