Huntsman spiders of the genus Sinopoda (Araneae, Sparassidae, Heteropodinae) from the Honghe Hani and Yi Autonomous Prefecture, southwestern China, with descriptions of two new species

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  Huntsman spiders of the genus Sinopoda (Araneae, Sparassidae, Heteropodinae) from the Honghe Hani and Yi Autonomous Prefecture, southwestern China, with descriptions of two new species Abstract Spiders of the genus Sinopoda Jäger, 1999 from Honghe Hani and Yi Autonomous Prefecture, Yunnan Province, China are studied. A total of four species are reported and illustrated of which two, Sinopoda honghe Yu & Zhong, sp. nov . and Sinopoda kuan Yu & Zhong, sp. nov ., are described as new to science. The other two previously described species from this region: S. tengchongensis Fu & Zhu, 2008 and S. tumefacta Zhong, Jäger, Chen & Liu, 2019 are also illustrated. Detailed descriptions, diagnoses, illustrations and DNA barcodes of the two new species are given. A distribution map of these four species in Honghe is provided. Zhang C, Xing Y, Zhong Y, Yu H (2026) Huntsman spiders of the genus Sinopoda (Araneae, Sparassidae, Heteropodinae) from the Honghe Hani and Yi ...

Crystal structure and functional characterization of an Asp49 phospholipase A2 from the bushmaster (Lachesis muta)

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Image Credit: By Christopher Murray - en:Image:Lachesis muta muta.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1120263

Crystal structure and functional characterization of an Asp49 phospholipase A2 from the bushmaster (Lachesis muta)

Snake-venom phospholipases A2 (PLA2s) are small, structurally conserved enzymes that contribute significantly to the pathophysiology of envenomation. Here, we report the purification and crystal structure of an Asp49-PLA2 isolated from the venom of Lachesis muta, a pit viper from the Peruvian Amazon. The enzyme was purified using ion-exchange and size-exclusion chromatography and exhibited phospholipase activity in a dose- and time-dependent egg-yolk degradation assay. Pure protein crystals were obtained in space group P6222 and diffracted to 2.36 Å resolution, with two molecules in the asymmetric unit. The structure reveals the canonical fold of catalytically active group II PLA2s, with a bound Ca2+ ion and a MES molecule in the active site of one monomer. Seven disulfide bonds stabilize the structure, although one bridge typically associated with the β-hairpin is absent and is replaced by a salt bridge as in other viperid PLA2s. PISA analysis suggests a potential tetrameric assembly composed of two AB dimers generating an interface between two A subunits (A–A′). Electrostatic surface mapping reveals a notable positively charged channel at the A–A′ interface, like that seen for a basic PLA2 homodimer from Crotalus durissus terrificus in which the two active sites lie accessible to the membrane. This study presents the first structural and enzymatic analysis of an Asp49-PLA2 from L. muta and provides insights into its oligomeric assembly, electrostatic landscape and potential adaptations relevant to its role in venom toxicity.

Neyra Chama, N. E., Romero Vargas, F. F., Condori Mamani, E., Vargas, J. A., Alves Furtado, A., D'Muniz Pereira, H., Navarro Oviedo, R. D., Garratt, R. C., Vega Ramirez, J. L. J. & Leonardo, D. A. (2026). Acta Cryst. F82. https://journals.iucr.org/f/issues/2026/05/00/nq5002/index.html