Proteomic Analysis of Heloderma horridum horridum Venom: Assessment to Its Transcriptome and Newfound Proteins.

Heloderma horridum horridum, a venomous reptile native to America, has a venom with potential applications in treating type II diabetes. In this work, H. h. horridum venom was extracted, lyophilized, and characterized using enzymatic assays for hyaluronidase, phospholipase, and protease. Proteomic analysis of the venom was conducted employing bottom-up/shotgun approaches, SDS-PAGE, high-pH reversed-phase chromatography, and fractionation of tryptic peptides using nano-LC-MS/MS. The proteins found in H. h. horridum venom were reviewed according to the classification of the transcriptome previously reported. The proteomic approach identified 101 enzymes, 36 other proteins, 15 protein inhibitors, 11 host defense proteins, and 1 toxin, including novel venom components such as calcium-binding proteins, phospholipase A2 inhibitors, serpins, cathepsin, subtilases, carboxypeptidase-like, aminopeptidases, glycoside hydrolases, thioredoxin transferases, acid ceramidase-like, enolase, multicopper oxidases, phosphoglucose isomerase (PGI), fructose-1,6-bisphosphatase class 1, pentraxin-related, peptidylglycine α-hydroxylating monooxygenase/peptidyl-hydroxyglycine α-amidating lyase, carbonic anhydrase, acetylcholinesterase, dipeptidylpeptidase, and lysozymes. These findings contribute to understanding the venomous nature of H. h. horridum and highlight its potential as a source of bioactive compounds. Data are available via PRoteomeXchange with the identifier PXD052417.

Cardiac alterations induced by Heloderma horridum horridum venom in rats: An experimental study with ECG analysis using a linear regression algorithm.

Envenomation by reptile venom, particularly from lizards, poses significant health risks and can lead to physiological and cardiovascular changes. The venom of Heloderma horridum horridum, endemic to Colima, Mexico, was tested on Wistar rats. Electrocardiographic (ECG) data were collected pre-treatment and at 5-min intervals for 1 h post-envenomation. A specially designed computational linear regression algorithm (LRA) was used for the segmentation analysis of the ECG data to improve the detection of fiducial points (P, Q, R, S, and T) in ECG waves. Additionally, heart tissue was analyzed for macroscopic and microscopic changes. The results revealed significant electrocardiographic alterations, including pacemaker migration, junctional extrasystoles, and intraventricular conduction aberrations. By applying a linear regression algorithm, the study compensated for noise and anomalies in the isoelectric line in an ECG signal, improving the detection of P and T waves and the QRS complex with an efficiency of 97.5%. Cardiac enzyme evaluation indicated no statistically significant differences between the control and experimental groups. Macroscopic and microscopic examination revealed no apparent signs of damage or inflammatory responses in heart tissues. This study enhances our understanding of the cardiovascular impact of Heloderma venom, suggesting a greater influence on changes in conduction and arrhythmias than on direct cardiac damage to the myocardium.

The diversity of venom components of the scorpion species Paravaejovis schwenkmeyeri (Scorpiones: Vaejovidae) revealed by transcriptome and proteome analyses.

The recent publication of high-throughput transcriptomic and proteomic analyses of scorpion venom glands has increased our knowledge on the biodiversity of venom components. In this contribution, we report the transcriptome of the venom gland and the proteome of the venom for the scorpion species Paravaejovis schwenkmeyeri, a member of the family Vaejovidae. We report 138 annotated transcripts encoding putative peptides/proteins with sequence identity to known venom components available from different databases. A fingerprint analysis containing the molecular masses of 212 components of the whole soluble venom revealed molecular weights of approximately 700 to 13,800 Da, with most detected proteins ranging from 1500 to 3000 Da. Amino acid sequencing of venom components by LC-MS/MS allowed the identification of fragments from 27 peptides encoded by transcripts found in the transcriptome analysis. Enzymatic assays conducted with the soluble venom fraction confirmed the presence of enzymes such as hyaluronidases and phospholipases. The database presented here increases our general knowledge on the biodiversity of venom components from neglected non-buthid scorpions.