# Comparative studies of the effects of Naja ashei venom-derived proteins on model and native lipid membranes

## TL;DR

This study explores how proteins from Naja ashei venom affect cancer cell membranes, showing that leukemia cells are more sensitive due to their lipid composition.

## Contribution

The study provides new insights into the membrane-level effects of less-studied SVMP and CRISP proteins from Naja ashei venom.

## Key findings

- Leukemia cell membranes were more susceptible to toxin-induced damage due to higher unsaturated lipid content.
- PLA₂, CRISP, and SVMP proteins alter membrane stiffness, elasticity, and surface charge in distinct ways.
- The effects of these proteins align with predictions from model lipid systems and highlight their potential for anticancer research.

## Abstract

Venoms contain toxins that are increasingly recognized as valuable sources of biologically active compounds. In this study, we examined the biochemical and biophysical properties of PLA₂, CRISP, and SVMP fractions isolated from Naja ashei venom with the detailed description of their interactions with cell membranes. By integrating these results with our previous analysis of the 3FTx fractions, we provide a broad and coherent overview of the most relevant protein components in N. ashei venom. Experiments were performed on two cancer cell lines with distinct membrane architectures: HL-60 (leukemia) and SK-N-SH (neuroblastoma). These lines differ particularly in membrane cholesterol content and in the saturation level of hydrophobic lipid parts. Our results enabled a comparative assessment of how each protein fraction modulates the mechanical and electrostatic properties of both model and native membranes. In agreement with predictions derived from model lipid systems, leukemia cell membranes were more susceptible to toxin-induced damage than neuroblastoma membranes, likely owing to their higher proportion of unsaturated lipids. Physicochemical analyses confirmed that the isolated PLA2, CRISP, and SVMP fractions alter key membrane parameters, including stiffness, elasticity, lipid-protein interactions, and the net charge of the polar headgroup region. Importantly, this work provides new insights into the membrane-level effects of SVMP and CRISP proteins, which have been less comprehensively studied compared with well characterized 3FTx and PLA₂ families. These results reveal distinct, cell membrane–dependent responses to N. ashei venom proteins and justify further basic research to better understand their action with cells.

Animal venoms contain many proteins that may serve as promising leads for developing new anticancer therapies. In this study, we examined how specific proteins isolated from Naja ashei venom interact with cancer cell membranes. We focused on two cell lines-HL-60 (leukemia) and SK-N-SH (neuroblastoma) - which differ in cholesterol levels and lipid saturation, two factors known to influence membrane sensitivity. The interaction between lipid membranes and toxins belonging to: PLA₂, CRISP, and SVMP families have been studied with the use of complementary techniques. The Langmuir method allowed us to observe how each protein affects the behavior of lipid monolayers, zeta potential measurements showed how they modify membrane surface charge, and LDH release assays revealed the degree of membrane permeability they induce. We also compared these effects with our earlier findings on three-finger toxins, a major component of N. ashei venom. Our results show a gradation in how the tested proteins influence membrane mechanics and electrostatics. PLA2, CRISP, and SVMP each produce distinct and measurable changes, some of which are more pronounced in leukemia cells, which have more unsaturated lipids and therefore more sensitive membranes. This study highlights how venom proteins can modify cancer cell membranes and identifies key toxin families as promising candidates for future research.