Venomics of Trimeresurus (Popeia) nebularis, the Cameron Highlands Pit Viper from Malaysia: Insights into Venom Proteome, Toxicity and Neutralization of Antivenom

Abstract

Trimeresurus nebularis is a montane pit viper that causes bites and envenomation to various communities in the central highland region of Malaysia, in particular Cameron’s Highlands. To unravel the venom composition of this species, the venom proteins were digested by trypsin and subjected to nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS) for proteomic profiling. Snake venom metalloproteinases (SVMP) dominated the venom proteome by 48.42% of total venom proteins, with a characteristic distribution of P-III: P-II classes in a ratio of 2:1, while P-I class was undetected. Snaclecs constituted the second most venomous protein family (19.43%), followed by snake venom serine proteases (SVSP, 14.27%), phospholipases A2 (5.40%), disintegrins (5.26%) and minor proteins including cysteine-rich secretory proteins, L-amino acid oxidases, phosphodiesterases, 5′-nucleotidases. The venomic profile correlates with local (painful progressive edema) and systemic (hemorrhage, coagulopathy, thrombocytopenia) manifestation of T. nebularis envenoming. As specific antivenom is unavailable for T. nebularis, the hetero-specific Thai Green Pit viper Monovalent Antivenom (GPVAV) was examined for immunological cross-reactivity. GPVAV exhibited good immunoreactivity to T. nebularis venom and the antivenom effectively cross-neutralized the hemotoxic and lethal effects of T. nebularis (lethality neutralizing potency = 1.6 mg venom per mL antivenom). The findings supported GPVAV use in treating T. nebularis envenoming.

Snake C-Type Lectins Potentially Contribute to the Prey Immobilization in Protobothrops mucrosquamatus and Trimeresurus stejnegeri Venoms

“…Viper snaclecs are one of the most abundant nonenzymatic group of proteins in some Viperidae venoms [8][9][10][11][12]. The Snaclecs reduced the exploratory behavior and locomotor activity of pheasant chicks as well as mice within 5 min of injection in a concentration-dependent manner, as shown in Figure 1.…”

“…Snake C-type lectin-like proteins (snaclecs) are mainly expressed in the venoms of vipers and colubrids [4,5]. The available data indicates that snaclecs may be one of the most abundant nonenzymatic group of proteins in the venoms [8][9][10][11][12][13]. Snalecs usually have a heterodimeric structure with α and β subunits, which are often oligomerized to form protein multimers, and have evolved to bind a wide range of physiologically important proteins such as GPIb, GPVI and integrins on mammal platelets [13][14][15][16].…”

Proteomics and antivenom immunoprofiling of Russell’s viper (Daboia siamensis) venoms from Thailand and Indonesia

“…On the other hand, the SVMP proteins constitute 2−3% of the total venom proteins in both D. siamensis venoms, comprising the factor X-activating enzyme which is a procoagulant protein that activates coagulation factor X, factor IX and protein S, thus contributing to the consumptive coagulopathic effect of the venom [45]. The low abundance of SVMP also implies that the venoms lack hemorrhagin proteins, unlike some Asiatic pit vipers whose venoms are known to cause intense dermal hemorrhage [29]. The significant presence of procoagulant SVSP and SVMP is consistent with the potent plasma-clotting effects and the absence of dermal hemorrhagic activity of both venoms from Ds-Thailand and Ds-Indonesia [22].…”

“…The abundance of individual venom toxin was estimated based on its mean spectral intensity (MSI) relative to the total MSI of all proteins identified through the in-solution mass spectrometry [28]. The relative abundance of individual venom protein within each chromatographic step was estimated based on the mean spectral intensity (MSI) of its peptides relative to the total MSI of all proteins detected in the fraction [29].…”

Venomics and Cellular Toxicity of Thai Pit Vipers (Trimeresurus macrops and T. hageni)

“…According to proteomics studies, each specific venom contains a unique variety of toxins [16]. To date, T. insularis (Indonesian), T. borneensis (Borneo), T. stejnegeri (Taiwan), T. puniceus (Java), T. purpureomaculatus (Thailand), T. gramineus (India), T. nebularis (Malaysia), and T. alborabris (Thailand) have been investigated for their venom constituents [17][18][19]. However, there is no reported information on the venomic protein profile of the Southeast Asia endemic species T. macrops and T. hageni.…”