Elucidating on the quaternary structure of viper venom phospholipase A2 enzymes in aqueous solution

• Type: Article in International Scientific Journal
• Date: 2025

Authors

da Silva, R (Author) Other; Ramos, MJ (Author) Other; Pedro A Fernandes (Author) FCUP

Journal

Title: Biochimie

ISSN: 0300-9084

Publisher: Elsevier

Indexing

Scopus - 0 Citations

Other information

Authenticus ID: P-017-THV

DOI: 10.1016/j.biochi.2024.12.015

Abstract (EN): This study focuses on the quaternary structure of the viper-secreted phospholipase A2 (PLA2), a central toxin in viper envenomation. PLA2 enzymes catalyze the hydrolysis of the sn-2 ester bond of membrane phospholipids. Small-molecule inhibitors that act as snakebite antidotes, such as varespladib, are currently in clinical trials. These inhibitors likely bind to the enzyme in the aqueous cytosol prior to membrane-binding. Thus, understanding its controversial solution structure is key for drug design. Crystal structures of PLA2 in the PDB show at least four different dimeric conformations, the most well-known being ¿extended¿ and ¿compact¿. This variability among enzymes with >50 % sequence identity raises questions about their transferability to aqueous solution. Therefore, we performed extensive molecular dynamics (MD) simulations of several PLA2 enzymes in water to determine their quaternary structure under physiological conditions. The MD simulations strongly indicate that PLA2 enzymes adopt a ¿semi-compact¿ conformation in cytosol, a hybrid between extended and compact conformations. To our knowledge, this is the first study that determines the most favorable dimeric conformation of PLA2 enzymes in solution, providing a basis for advancements in snakebite envenoming treatment. Recognizing snakebite envenoming as a neglected tropical disease has driven the search for efficient, affordable alternatives to the current antivenoms. Therefore, understanding the main drug targets within snake venom is crucial to this achievement. © 2025 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM)

Language: English

Type (Professor's evaluation): Scientific