Venom Proteomics of Trimeresurus gracilis, a Taiwan-Endemic Pitviper, and Comparison of Its Venom Proteome and VEGF and CRISP Sequences with Those of the Most Related Species

Trimeresurus gracilis is an endemic alpine pitviper in Taiwan with controversial phylogeny, and its venom proteome remains unknown. In this study, we conducted a proteomic analysis of T. using high-performance liquid chromatography-tandem mass spectrometry identified 155 toxin proteoforms that belong to 13 viperid families. By searching the sequences trypsin-digested peptides separated HPLC fractions against NCBI database, was found contain 40.3% metalloproteases (SVMPs), 15.3% serine proteases, 6.6% phospholipases A2, 5.0% l-amino acid oxidase, 4.6% Cys-rich secretory proteins (CRISPs), 3.2% disintegrins, 2.9% vascular endothelial growth factors (VEGFs), 1.9% C-type lectin-like proteins, 20.2% minor toxins, nontoxins, unidentified or compounds. Sixteen these matched toxins whose full amino-acid have been deduced from gland cDNA sequences. The hemorrhagic appears be especially rich PI-class SVMPs lacks basic phospholipase A2. We also cloned sequenced cDNAs encoding two CRISP three VEGF variants glands. Sequence alignments comparison revealed PI-SVMP, kallikrein-like CRISPs, VEGF-F Ovophis okinavensis are structurally most similar, consistent their close phylogenetic relationship. However, expression levels some were rather different, possibly due distinct ecological prey conditions.