Proteolysis in vitro of human hemoglobins A, F and S by the cerastes [Egyptian sand viper] snake venom

ABSTRACT

Hemoglobins [Hbs] gain their importance not only for being vital oxygen transporters but also for being ideal molecules to study the structure-function relationship of proteins. The effect of snake venom from Cerastes cerastes was examined on human hemoglobins A, F and the most common hemoglobin variant hemoglobin S. The crude venom was able to degrade the intact hemoglobin molecules. Hemoglobins F, A, and S were completely digested by four hours incubation with the venom protease[s]. Ail digested hemoglobins showed more cathodic products in comparison with the intact molecules. The proteolytic activity of Cerastes cerastes was detected in the first three peaks efuted from sephadex G 100 column. Digestion of Hb F and S was not affected by EDTA or 1,3 difioro-2-propanol. Hb A degradation was partially inhibited by EDTA but not with 1,3 difloro-2-propanol. lodoacetamide was able to inhibit the proteolytic effect on both Hb A and F