Venomics of the milos viper (Macrovipera schweizeri) unveils patterns of venom composition and exochemistry across blunt-nosed viper venoms

Abstract

Introduction: Snakebite is a neglected tropical disease and a globally important driver of death and morbidity. Vipers of the genus Macrovipera (Viperidae: Viperinae) are among the snakes of higher medical importance in the Old World. Despite the medical relevance of Macrovipera venoms, the knowledge regarding them is heterogeneously distributed with virtually all works conducted so far focusing on subspecies of Macrovipera lebetinus, while other species within the genus are largely overlooked. Here we present the first proteomic evaluation of the venom from the Greek endemic Milos viper (Macrovipera schweizeri). In line with clinical symptoms typically elicited by Macrovipera envenomations, Milos viper venom primarily comprises coagulotoxic and cytotoxic protein families, such as metalloproteinases (svMP) and serine proteases (svSP).Methods: We conducted comparative bioactivity assays on venoms from M. schweizeri and the M. lebetinus subspecies M. lebetinus cernovi, M. lebetinus obtusa, and M. lebetinus turanica, and showed that they all exhibit similarities in levels of cytotoxicity proteolytic activity, and inhibition of prokaryotic growth. Lastly, we compared Macrovipera venom profiles by 1D-SDS-PAGE and RP-HPLC, as well as our proteomic data with previously published Macrovipera venom proteomes.Results and discussion: The analyzes performed to reveal that a general venom profile seems to be conserved across blunt-nosed vipers, and that, M. schweizeri envenomations, similarly to those caused by other blunt-nosed vipers, are able to cause significant tissue damage. The present work represents an important starting point for the development of comparative studies across the full taxonomic range of the genus Macrovipera and can potentially help optimize the treatment of envenomations caused by M. schweizeri.

Venomics and Peptidomics of Palearctic vipers: Clade-wide analysis of seven taxa of the generaVipera,Montivipera,MacroviperaandDaboiaacross Türkiye

“…A detailed genus-wide comparison of all blunt-nose vipers venoms has been published recently in tandem with a detailed biochemical and pharmacological overview of M. lebetinus ssp. toxins 129,130 . Thus, these aspects will only be briefly discussed here.…”

“…It should be emphasized that Macrovipera has the largest DI amount of the four genera with a consistently high content of 11-16%, independently to the DI subfamily composition. Although the expected monomeric, KTS sequence containing short DI obtustatin was originally characterized as high abundant toxin of M. l. obtusa (unreported local origin) with 7% of the whole venom proteome, no short nor monomeric DI has been described until now for any Turkish and Iranian Macrovipera venom 129,131 , while several R/KTS DI are even known from other Viperidae venoms, including recently Vipera 114,132 . Similarly, the venoms of another Turkish M. l. obtusa location and an Iranian M. l. cernovi lack small DI, while the Russian and Armenian M. l. obtusa contain them 129 .…”

“…Although the expected monomeric, KTS sequence containing short DI obtustatin was originally characterized as high abundant toxin of M. l. obtusa (unreported local origin) with 7% of the whole venom proteome, no short nor monomeric DI has been described until now for any Turkish and Iranian Macrovipera venom 129,131 , while several R/KTS DI are even known from other Viperidae venoms, including recently Vipera 114,132 . Similarly, the venoms of another Turkish M. l. obtusa location and an Iranian M. l. cernovi lack small DI, while the Russian and Armenian M. l. obtusa contain them 129 . This indicates that the subfamily of monomeric R/KTS DI is diversely distributed even within the genus Macrovipera .…”

Comparative venom analysis between melanistic and normally-colored phenotypes of the common adder (Vipera berus)

“…Compositional venom profiling was carried out as previously described (Schulte et al, 2023) by combining reducing and non-reducing sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) with 5 µg of each sample and reversed-phase high-performance liquid chromatography (RP-HPLC) with 125 µg of each sample. Chromatograms (280 nm) were normalized against an initial equilibration run to reduce noise.…”

“…no. 539125) for 96-well plates as previously described (Schulte et al, 2023). Venoms were redissolved in double-distilled water and added in triplicates at final concentrations of 25, 50, 100, 200 and 400 µg/ml, as described above.…”