Centruroides possanii is a recently discovered species of “striped scorpion” found in Mexico. Certain species of Centruroides are known to be toxic to mammals, leading to numerous cases of human intoxications in the country. Venom components are thought to possess therapeutic potential and/or biotechnological applications. Hence, obtaining and analyzing the secretory gland transcriptome and venom proteome of C. possanii is relevant, and that is what is described in this communication. Since this is a newly described species, first, its LD₅₀ to mice was determined and estimated to be 659 ng/g mouse weight. Using RNA extracted from this species and preparing their corresponding cDNA fragments, a transcriptome analysis was obtained on a Genome Analyzer (Illumina) using the 76-base pair-end sequencing protocol. Via high-throughput sequencing, 19,158,736 reads were obtained and ensembled in 835,204 sequences. Of them, 28,399 transcripts were annotated with Pfam. A total of 244 complete transcripts were identified in the transcriptome of C. possanii. Of these, 109 sequences showed identity to toxins that act on ion channels, 47 enzymes, 17 protease inhibitors (PINs), 11 defense peptides (HDPs), and 60 in other components. In addition, a sample of the soluble venom obtained from this scorpion was analyzed using an Orbitrap Velos apparatus, which allowed for identification by liquid chromatography followed by mass spectrometry (LC-MS/MS) of 70 peptides and proteins: 23 toxins, 27 enzymes, 6 PINs, 3 HDPs, and 11 other components. Until now, this work has the highest number of scorpion venom components identified through omics technologies. The main novel findings described here were analyzed in comparison with the known data from the literature, and this process permitted some new insights in this field.

Respiratory diseases in ruminants are a main cause of economic losses to farmers worldwide. Approximately 25% of ruminants experience at least one episode of respiratory disease during the first year of life. Mannheimia haemolytica is the main etiological bacterial agent in the ruminant respiratory disease complex. M. haemolytica can secrete several virulence factors, such as leukotoxin, lipopolysaccharide, and proteases, that can be targeted to treat infections. At present, little information has been reported on the secretion of M. haemolytica A2 proteases and their host protein targets. Here, we obtained evidence that M. haemolytica A2 proteases promote the degradation of hemoglobin, holo-lactoferrin, albumin, and fibrinogen. Additionally, we performed biochemical characterization for a specific 110 kDa Zn-dependent metalloprotease (110-Mh metalloprotease). This metalloprotease was purified through ion exchange chromatography and characterized using denaturing and chaotropic agents and through zymography assays. Furthermore, mass spectrometry identification and 3D modeling were performed. Then, antibodies against the 110 kDa-Mh metalloprotease were produced, which achieved great inhibition of proteolytic activity. Finally, the antibodies were used to perform immunohistochemical tests on postmortem lung samples from sheep with suggestive histology data of pneumonic mannheimiosis. Taken together, our results strongly suggest that the 110-Mh metalloprotease participates as a virulence mechanism that promotes damage to host tissues.

Gallibacterium anatis is a Gram-negative bacterium that is a pathogen and part of the microbiome of both domestic and wild birds. It is also the cause of reproductive infections, primarily when birds are stressed. Its pathogenicity has been associated with the expression of virulence factors. The effect of epinephrine (Epi) and norepinephrine (NEpi) hormones on the composition and structure of G. anatis biofilms is evaluated here. Catecholamines induced compaction and fragmentation of biofilms at 24 h. Biofilm amount diminishes (50%) by NEpi. At 48 h, biofilm fragments are immersed in exopolymer material, and the control biofilm shows a high quantity of filamentous cells, not observed with hormones. Enzymatic digestion of biofilm polymers showed increased protein levels in the presence of Epi at 24 or 48 h and NEpi at 24 or 72 h. Epi increased carbohydrate quantity, but NEpi diminished, and DNA quantities diminished at 48 h by Epi. Epi diminishes the expression of proteins in the 70–200 kDa range but increases the expression of secreted proteins. NEpi induces proteolytic activity in the range of 20–110 kDa. A 55 kDa protease was induced at 72 h by both hormones. Gallibacterium anatis biofilm changes could be significant in its dispersion and pathogenesis.

Nematode-trapping fungi have emerged as biological alternatives to address the increasing problem of antiparasitic drug resistance. These fungi develop three-dimensional adhesive networks that capture, kill, and digest nematodes. In addition, they employ other mechanisms to degrade their prey, including proteolytic enzymes. Arthrobotrys oligospora is recognized as one of the most effective biological control agents against both free-living and gastrointestinal parasitic nematodes. However, little is currently known about the proteases associated with its mycelium. The objective of this work was the identification and purification of the 78.9 kDa from A. oligospora. In this study, we provide the first evidence that A. oligospora mycelium exhibits two distinct proteolytic activities, corresponding to 78.9 and 250 kDa, revealed by zymography analysis. These proteases displayed activity over different pH ranges, suggesting distinct biochemical properties. The 78.9 kDa protease was subsequently purified by ion-exchange chromatography and biochemically characterized. Inhibition assays demonstrated that it belongs to the Zn-metalloproteases, a finding subsequently confirmed by mass spectrometry. We also performed a 3D modeling prediction and identified its potential zinc-binding sites. Finally, molecular docking analyses demonstrate that this enzyme exhibits a high binding affinity for chitin, suggesting chitinase activity; thus, it could be a key component in the degradation of nematode structural components during fungal predation.