Comprehensive snake venomics of the Okinawa Habu pit viper, Protobothrops flavoviridis, by complementary mass spectrometry-guided approaches

Abstract

Abstract:The Asian world is home to a multitude of venomous and dangerous snakes, which are attributed to various medical effects used in the preparation of traditional snake tinctures and alcoholics, like the Japanese snake wine, named Habushu. The aim of this work was to perform the first quantitative proteomic analysis of the Protobothrops flavoviridis pit viper venom. Accordingly, the venom was analyzed by complimentary bottom-up and top-down mass spectrometry techniques. The mass spectrometry-based snake venomics approach revealed that more than half of the venom is composed of different phospholipases A2 (PLA2). The combination with an intact mass profiling led to the identification of the three main Habu PLA2s. Furthermore, nearly one-third of the total venom consists of snake venom metalloproteinases and disintegrins, and several minor represented toxins families were detected: CTL, CRISP, svSP, LAAO, PDE and 5'-nucleotidase. Finally, the venom of P. flavoviridis contains certain bradykinin-potentiating peptides and related peptides, like the svMP inhibitors pEKW, pEQW, pEEW and pENW. In preliminary MTT cytotoxicity assays the highest cancerous-cytotoxicity of the crude venom was measured against human neuroblastoma SH-SY5Y cells and shows in some fractions disintegrin-like effects.