Electrophysiological and Proteomic Studies of Protobothrops mangshensis Venom Revealed Its High Bioactivities and Toxicities

Snake venoms contain rich components having medical and biotechnological values. The proteomic characterization of snake venom proteome has thus potential benefits for basic research, clinical diagnosis, and development of new drugs for a variety of diseases. Protobothrops mangshensis is a monotypic genus of pit viper known only from Mountain Mang in Hunan Province of China, and represents the largest and the most spectacular snake among Asian venomous snakes. The venom of Protobothrops mangshensis exhibits a high coagulant activity on bovine and human fibrinogen and human plasma, a high phosphodiesterase activity and an arginine ester hydrolytic activity. In this study, the Protobothrops mangshensis venom was analyzed by 2D-gel electrophoresis separation, subsequently by in-gel digestion, MS/MS identification, and enzymatic activity analysis. Our results demonstrated that Protobothrops mangshensis venom comprised highly functional proteins and/or enzymes, and each of these proteins displayed multiple isoforms separated in 2-DE. Approximately 59.4% of the identified total 143 proteins had enzymatic activities and 24.5% were involved ion channels, representing highly complex and extensive bioactivities of the snake venom. The identified toxins included six protein families: serine proteinases, L-amino acid oxidase, phospholipases A2, C-type lectin-like proteins, cysteine-rich secretory proteins and metalloproteinase-disintegrin, and were correlated well with the clinical manifestations by Protobothrops mangshensis bite such as coagulopathy, oedema, hypotensive and tissue damaging effects. Electrophysiological studies showed that the snake venom inhibited tetrodotoxin-resistant (TTX-R) Na+ currents. All our results in this study provided the first functional proteomics of Protobothrops mangshensis venom