In Memoriam: Giraldo Alayón García

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  In Memoriam: Giraldo Alayón García -  Photo © Facebook/National Museum of Natural History of Cuba In Memoriam: Giraldo Alayón García The arachnological community mourns the loss of Giraldo Alayón García, a Cuban zoologist whose work helped bring the spiders of Cuba and the wider Caribbean into clearer scientific view. As a researcher and curator at Cuba’s National Museum of Natural History, Dr. Alayón devoted decades to studying arachnids. His publications on spider taxonomy, evolution, and biogeography gave other researchers a stronger foundation for understanding the region’s biodiversity. He also shared that knowledge through teaching and scientific exchange far beyond Cuba. For those of us who care about taxonomy, his legacy is a reminder of the patient work behind every species description: examining specimens, recording differences, and preserving knowledge that others can build upon. His contributions will continue to guide the study of Caribbean spiders for years to ...

Comparative Biochemical, Structural, and Functional Analysis of Recombinant Phospholipases D from Three Loxosceles Spider Venoms

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Comparative Biochemical, Structural, and Functional Analysis of Recombinant Phospholipases D from Three Loxosceles Spider Venoms

Abstract

Spiders of Loxosceles genus are widely distributed and their venoms contain phospholipases D (PLDs), which degrade phospholipids and trigger inflammatory responses, dermonecrosis, hematological changes, and renal injuries. Biochemical, functional, and structural properties of three recombinant PLDs from L. intermedia, L. laeta, and L. gaucho, the principal species clinically relevant in South America, were analyzed. Sera against L. gaucho and L. laeta PLDs strongly cross-reacted with other PLDs, but sera against L. intermedia PLD mostly reacted with homologous molecules, suggesting underlying structural and functional differences. PLDs presented a similar secondary structure profile but distinct melting temperatures. Different methods demonstrated that all PLDs cleave sphingomyelin and lysophosphatidylcholine, but L. gaucho and L. laeta PLDs excelled. L. gaucho PLD showed greater “in vitro” hemolytic activity. L. gaucho and L. laeta PLDs were more lethal in assays with mice and crickets. Molecular dynamics simulations correlated their biochemical activities with differences in sequences and conformations of specific surface loops, which play roles in protein stability and in modulating interactions with the membrane. Despite the high similarity, PLDs from L. gaucho and L. laeta venoms are more active than L. intermedia PLD, requiring special attention from physicians when these two species prevail in endemic regions.

da Justa, Hanna Câmara, Jorge Enrique Hernández González, Larissa Vuitika, Ricardo Barros Mariutti, Pedro Augusto Martinho Magnago, Fábio Rogério de Moraes, Andrea Senff-Ribeiro, Luiza Helena Gremski, Raghuvir Krishnaswamy Arni, and Silvio Sanches Veiga. 2023. "Comparative Biochemical, Structural, and Functional Analysis of Recombinant Phospholipases D from Three Loxosceles Spider Venoms" International Journal of Molecular Sciences 24, no. 15: 12006. https://doi.org/10.3390/ijms241512006