Charaterization of bumarsin, a 3-hydroxy-3-methylglutaryl-coenzyme reductase inhibitor from Mesobuthus martensii Karsch venom

First transcriptome analysis of the venom glands of the scorpion Hottentotta zagrosensis (Scorpions: Buthidae) with focus on venom lipolysis activating peptides

Introduction

Scorpion venom is a rich source of biological active peptides and proteins. Transcriptome analysis of the venom gland provides detailed insights about peptide and protein venom components. Following the transcriptome analysis of different species in our previous studies, our research team has focused on the Hottentotta zagrosensis as one of the endemic scorpions of Iran to obtain information about its venom proteins, in order to develop biological research focusing on medicinal applications of scorpion venom components and antivenom production. To gain insights into the protein composition of this scorpion venom, we performed transcriptomic analysis.

Methods

Transcriptomic analysis of the venom gland of H. zagrosensis, prepared from the Khuzestan province, was performed through Illumina paired-end sequencing (RNA-Seq), Trinity de novo assembly, CD-Hit-EST clustering, and annotation of identified primary structures using bioinformatics approaches.

Results

Transcriptome analysis showed the presence of 96.4% of complete arthropod BUSCOs, indicating a high-quality assembly. From total of 45,795,108 paired-end 150 bp trimmed reads, the clustering step resulted in the generation of 101,180 de novo assembled transcripts with N50 size of 1,149 bp. 96,071 Unigenes and 131,235 transcripts had a significant similarity (E-value 1e-3) with known proteins from UniProt, Swissprot, Animal toxin annotation project, and the Pfam database. The results were validated using InterProScan. These mainly correspond to ion channel inhibitors, metalloproteinases, neurotoxins, protease inhibitors, protease activators, Cysteine-rich secretory proteins, phospholipase A enzymes, antimicrobial peptides, growth factors, lipolysis-activating peptides, hyaluronidase, and, phospholipase D. Our venom gland transcriptomic approach identified several biologically active peptides including five LVP1-alpha and LVP1-beta isoforms, which we named HzLVP1_alpha1, HzLVP1_alpha2, HzLVP1_alpha3, HzLVP1_beta1, and HzLVP1_beta and have extremely characterized here.

Discussion

Except for HzLVP1_beta1, all other identified LVP1s are predicted to be stable proteins (instability index <40). Moreover, all isoform of LVP1s alpha and beta subunits are thermostable, with the most stability for HzLVP1_alpha2 (aliphatic index = 71.38). HzLVP1_alpha2 has also the highest half-life. Three-dimensional structure of all identified proteins compacts with three disulfide bridges. The extra cysteine residue may allow the proteins to form a hetero- or homodimer. LVP1 subunits of H. zagrosensis potentially interact with adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), two key enzymes in regulation of lipolysis in adipocytes, suggesting pharmacological properties of these identified proteins.

Identification, classification, and characterization of alpha and beta subunits of LVP1 protein from the venom gland of four Iranian scorpion species

Scorpion venoms contain bioactive peptides and proteins. Some, can be used for pharmaceutical purposes. So, identification of venom proteins matters because, in addition to determining the function of the toxins can also be an excellent guide to developing new drugs. Here, we got transcriptome of venom glands from four Iranian scorpion species, including Hemsicorpius lepturus, Mesobuthus eupeus, Andructunus crassicuada, and Hottentotta saulcyi using cDNA library synthesis and high-throughput transcriptomic analysis of the venom glands. In a comparative way, we identified the cDNA encoding isoforms of subunits (alpha and beta) of BotLVP1/BmLVP1-like protein in the venom gland of three species except for H. lepturus. Characterization and structure determination of the LVP1_like proteins combined with gene map analysis provided evidence of the existence of some isoforms of LVP1_like proteins, encoded by genes with two exons and one intron, which can be classified in CSαβ superfamily in the venom gland of three Iranian scorpion species. According to the high similarity with BotLVP1 and BmLVP1, these proteins could also be potent to mediate cholesterol homeostasis. However, further research is needed to prove it, and this study just may lay the foundation lead to light up this way.

An overview of Tityus cisandinus scorpion venom: Transcriptome and mass fingerprinting reveal conserved toxin homologs across the Amazon region and novel lipolytic components

Tityus cisandinus, a neglected medically important scorpion in Ecuadorian and Peruvian Amazonia, belongs to a complex of species related to the eastern Amazon endemic Tityus obscurus, spanning a distribution of ca. 4000 km. Despite high morbidity and mortality rates, no effective scorpion antivenom is currently available in the Amazon region. Knowledge of the structural/functional relationships between T. cisandinus venom components and those from related Amazonian species is crucial for designing region-specific therapeutic antivenoms. In this work, we carried out the first venom gland transcriptomic study of an Amazonian scorpion outside Brazil, T. cisandinus. We also fingerprinted its total venom through MALDI-TOF MS, which supported our transcriptomic findings. We identified and calculated the expression level of 94 components: 60 toxins, 25 metalloproteases, five disulfide isomerases, three amidating enzymes, one hyaluronidase, and also uncovered transcripts encoding novel lipolytic beta subunits produced by New World buthid scorpions. This study demonstrates the high similarity between T. cisandinus and T. obscurus venoms, reinforcing the existence of a neglected complex of genetically and toxinologically related Amazonian scorpions of medical importance. Finally, we demonstrated the low recognition of currently available therapeutic sera against T. cisandinus and T. obscurus venoms, and concluded that these should be improved to protect against envenomation by Amazonian Tityus spp.

Peptides with therapeutic potential in the venom of the scorpion Buthus martensii Karsch

The scorpion Buthus martensii Karsch (BmK) has generated significant interest due to the presence of biologically active peptides in its venom. In the past decade, dozens of different peptides from BmK have been identified. Most of the peptides are neurotoxins and are responsible for the toxicity of BmK venom. Other peptides, including neurotoxins and non-disulfide-bridged peptides, show potential anticancer, antimicrobial, analgesic, and anti-epileptic therapeutic effects. These peptides are attractive candidates for drug development, and peptide derivatives have also been designed to enhance their therapeutic potential, such as ADWX-1 and Kn2-7. In this review, we provide an overview of the most promising peptides found in BmK venom and of modified peptide derivatives showing therapeutic potential.

Scorpion Venom Causes Upregulation of p53 and Downregulation of Bcl-xL and BID Protein Expression by Modulating Signaling Proteins Erk1/2 and STAT3, and DNA Damage in Breast and Colorectal Cancer Cell Lines

Scorpion venoms efficiently block the normal neurotransmitter signaling pathway by prejudicing the ion channel operating mechanism in the body system. Besides its negative effect, venoms also possess some beneficial qualities for humans. They have also been shown to exhibit anticancer properties in various cancer types. This unique property of the venom as an anticancer agent is mainly a result of its role in initiating apoptosis and inhibiting several signaling cascade mechanisms that promote cancer cell proliferation and growth. In this study, we examine the effect of venom on phenotypic changes as well as changes at the molecular levels in colorectal and breast cancer cell lines. A dramatic decrease in cell invasion was observed in both cancer cell lines on venom treatment. Additionally, there was decrease in IL-6, RhoC, Erk1/2, and STAT3 in venom-treated cell lines, providing strong evidence of its anticancer properties. Furthermore, decrease in the expression of antiapoptotic proteins and also upregulation of proapoptotic ones by these lines were observed on venom treatment. Moreover, a vivid picture of DNA damage was also detected on venom treatment. In conclusion, scorpion venom possesses significant potential as an anticancer agent against colorectal and breast cancer cell lines.

Proteomic analysis of the venom from the scorpion Mesobuthus martensii

The scorpion Mesobuthus martensii is the most populous species in eastern Asian countries, and several toxic components have been identified from their venoms. Nevertheless, a complete proteomic profile of the venom of M. martensii is still not available. In this study, the venom of M. martensii was analyzed by comprehensive proteomic approaches. 153 fractions were isolated from the M. martensii venom by 2-DE, SDS-PAGE and RP-HPLC. The ESI-Q-TOF MS results of all fractions were used to search the scorpion genomic and transcriptomic databases. Totally, 227 non-redundant protein sequences were unambiguously identified, composed of 134 previously known and 93 previously unknown proteins. Among 134 previously known proteins, 115 proteins were firstly confirmed from the M. martensii crude venom and 19 toxins were confirmed once again, involving 43 typical toxins, 7 atypical toxins, 12 venom enzymes and 72 cell associated proteins. In typical toxins, 7 novel-toxin sequences were identified, including 3 Na(+)-channel toxins, 3K(+)-channel toxins and 1 no-annotation toxin. These results increased 230% (115/50) venom components compared with previous studies from the M. martensii venom, especially 50% (24/48) typical toxins. Additionally, a mass fingerprint obtained by MALDI-TOF MS indicated that the scorpion venom contained more than 200 different molecular mass components.

BIOLOGICAL SIGNIFICANCE

This work firstly gave a systematic investigation of the M. martensii venom by combined proteomics strategy coupled with genomics and transcriptomics. A large number of protein components were unambiguously identified from the venom of M. martensii, most of which were confirmed for the first time. We also contributed 7 novel-toxin sequences and 93 protein sequences previously unknown to be part of the venom, for which we assigned potential biological functions. Besides, we obtained a mass fingerprint of the M. martensii venom. Together, our study not only provides the most comprehensive catalog of the molecular diversity of the M. martensii venom at the proteomic level, but also enriches the composition information of scorpion venom.