DETERMINATION OF THE ACTIVITY OF PROTEASES AND L-AMINO ACID OXIDASE (LAAO) IN THE VENOM OF COLUBER SNAKES AND THEIR MEDICAL SIGNIFICANCE

Abstract

Background: Snake venoms are complex mixtures of bioactive proteins and enzymes. While much attention has been given to vipers and elapids, the venom of Coluber snakes (non-venomous to mildly venomous rear-fanged colubrids) remains underexplored. Among their enzymatic components, proteases and L-amino acid oxidase (LAAO) play crucial roles in prey immobilization, tissue damage, and potential pharmacological applications. Objective: To quantitatively determine protease and LAAO activities in the venom of two Coluber species (C. jugularis and C. karelini) collected in Uzbekistan and to evaluate their medical significance based on clinical cases at Tashkent State Medical University (TSMU) clinics. Methods: Venom was extracted from 15 adult specimens. Protease activity was measured using casein and azocasein substrates. LAAO activity was determined using L-leucine as substrate and peroxidase-coupled assay. Clinical data from 12 patients envenomed by Coluber snakes between 2020–2025 were analyzed. Results: C. jugularis venom showed significantly higher protease activity (0.48 ± 0.05 U/mg) compared to C. karelini (0.29 ± 0.03 U/mg). LAAO activity was 0.32 ± 0.04 U/mg and 0.18 ± 0.02 U/mg, respectively. Protease activity correlated with local edema and hemorrhage (r=0.72, p<0.01). LAAO activity correlated with oxidative stress markers (MDA levels r=0.68, p<0.01). Conclusion: Coluber venom exhibits moderate but clinically relevant protease and LAAO activities. These enzymes contribute to local tissue damage and systemic inflammatory responses. Understanding their activity profiles aids in developing targeted antivenoms and exploring therapeutic applications.