Forstner, M. | Search bioRxiv

bioRxiv2026

Snake Venom Fluidic Properties and Design of Venom Mimics as Rheological Surrogates

Snake venom composition and its contribution to toxic effects has been heavily researched, but there is a comparative lack of information on venoms fluidic properties and their relationship with fang morphology during the envenomation process. Understanding how venom flows through a fang can shed light on bite site dynamics and potentially explain bite symptoms. In this article we first conduct a broad comparative test of the rheological properties of venom from thirteen snake species, including multiple viperid and elapid snake species, revealing a shear-thinning non-Newtonian flow behavior in all studied species. However, we have not observed strong phylogenetic signal in venom fluidic properties, suggesting that flow properties may vary independently of evolutionary relationships between snake species. Second, we demonstrate that snake venoms fluidic properties can be modeled by other inexpensive, safe, and abundant shear-thinning surrogate fluids. We found that aqueous solutions of bovine serum albumin protein and xanthan gum are useful venom mimics, matching the rheological behavior of venoms from the studied snake species across a range of relevant shear rates. We further evaluated the performance of these snake venom mimics in a simulated venom delivery system, showing good and robust mimetic control of the flow properties as a function of applied pressure. By elucidating the fluidic properties of snake venom and providing a non-toxic, scalable surrogate fluid model to be used in further studies, we provide the biomedical, toxicology, evolutionary biology communities with a tool to study envenomation physics in an inexpensive and safe fashion. We suggest it is possible to design species-specific venom mimics that facilitate research on the biomechanics and fluid dynamics of venom delivery via snake bites, and inform the design of bioinspired puncture and injection devices.

bioengineering↗

bioRxiv2021

The Unconventional Self-Cleavage of Selenoprotein K

Through known association with other proteins, human selenoprotein K (selenok) is currently implicated in the palmitoylation of proteins, degradation of misfolded proteins, innate immune response, and the life cycle of SARS-CoV-2 virus. However, neither the catalytic function of selenoks selenocysteine (Sec), which, curiously, resides in an intrinsically disordered protein segment nor selenoks specific role in these pathways are known to date. This report casts these questions in a new light as it describes that selenok is able -both in vitro and in vivo- to cleave some of its own peptide bonds. The cleavages not only release selenok segments that contain its reactive Sec, but as the specific cleavage sites were identified, they proved to cluster tightly near sites through which selenok interacts with protein partners. Furthermore, it is shown that selenoks cleavage activity is neither restricted to itself nor promiscuous but selectively extends to at least one of its protein partners. Together, selenoks cleavage ability and its features have all hallmarks of a regulatory mechanism that could play a central role in selenoks associations with other proteins and its cellular functions overall.

biochemistry↗