Application of Crotalus atrox venom α-protease for amino acid sequence determination

Abstract

The α-protease from Crotalus atrox snake venom has useful applications in amino acid sequence analysis. The enzyme, readily available by column chromatography of crude venom on DEAE-Sephadex, hydrolyzes bonds of the amino groups of aliphatic hydrophobic amino acids, preferentially at leucine, isoleucine, and valine. Since peptides smaller than five amino acid residues are not hydrolyzed by α-protease, “overlapping” peptides are obtained in high yields. The separation of the α-protease peptides by paper electrophoresis and subsequent direct Edman degradation by the paper strip method has proved valuable in sequence analysis in our laboratory.