Molecular Recognition and Immunopharmacological Implications of Serratiopeptidase Targeting Snake Venom Bradykinin-Potentiating Peptides

Posted by
  Molecular Recognition and Immunopharmacological Implications of Serratiopeptidase Targeting Snake Venom Bradykinin-Potentiating Peptides Abstract Purpose Bradykinin-potentiating peptides (BPPs), found in snake venom, are known to modulate cardiovascular functions, but their susceptibility to enzymatic degradation remains poorly understood. Methods Models were generated using AlphaFold-Colab for five small BPPs (< 9 amino acids) that did not have experimentally solved structures, and those BPPs which had reliable predictions of structure (pLDDT > 80) were used for docking studies. Protein-peptide docking experiments were done using HADDOCK for studying the interaction between wild-type (WT) and mutant serratiopeptidase with BPPs. After selecting the best complex, simulation of the complex was done using molecular dynamics (MD) simulations for 100 ns and binding energy determination using MM/PBSA analysis. For checking the mechanical stability of the protein-peptide complexes...

Phase response curve and RNA-sequencing demonstrate spiders’ sensitivity to light and pinpoint candidate light-responsive genes

Posted by

 


Phase response curve and RNA-sequencing demonstrate spiders’ sensitivity to light and pinpoint candidate light-responsive genes

Abstract

Spiders can maintain a wide range of free-running periods while still being entrained to a 24-hour day. To investigate the underlying mechanism of this entrainment, we constructed the phase-response curve (PRC) for the orb weaver, Metazygia wittfeldae, by subjecting the spiders to one-hour light pulses at various times throughout the circadian day. The resulting type 0 PRC showed high amplitude (> 6 hour) phase advance and delays when the light pulse was applied during circadian time (CT) 16–18, including a break point of delays to advances. We then investigated the genetic mechanism of response to light by splitting M. wittfeldae adult females entrained to 12 hours light:12 hours dark (LD 12:12) into two groups. One group received a 1-hour light pulse 5 hours after lights off (equivalent to CT17), and the other group did not. We then sacrificed spiders for RNA isolations 1 and 10 hours after the light pulse. We identified numerous genes that were downregulated by the light pulse 1 hour after the pulse relative to no pulse group. Intriguingly, many of these genes had a flipped pattern of expression 9 hours later – the pulse group had higher expression than the no pulse group. We also identified clock gene homologs in M. wittfeldae that had distinct expression patterns from other arthropods.

Citation: Toporikova N, Cheng W, Qian L, Mah A, Clarke T, Jones TC, et al. (2026) Phase response curve and RNA-sequencing demonstrate spiders’ sensitivity to light and pinpoint candidate light-responsive genes. PLoS One 21(9): e0344063. https://doi.org/10.1371/journal.pone.0344063