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

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.