Unveiling the Protein Components of the Secretory-Venom Gland and Venom of the Scorpion Centruroides possanii (Buthidae) through Omic Technologies.

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.

Indolealkylamines in the venom of the scorpion Thorellius intrepidus.

Scorpions are a group of arthropods that strike fear in many people due to their severe medical symptoms, even death, caused by their venomous stings. Even so, not all scorpion species contain harmful venoms against humans but still have valuable bioactive molecules, which could be used in developing new pharmaceutical leads for treating important diseases. This work conducted a comprehensive analysis of the venom from the scorpion Thorellius intrepidus. The venom of T. intrepidus was separated by size exclusion chromatography, and four main fractions were obtained. Fraction IV (FIV) contained small molecules representing over 90% of the total absorbance at 280 nm. Analysis of fraction FIV by RP-HPLC indicated the presence of three main molecules (FIV.1, FIV.2, and FIV.3) with similar UV absorbance spectra profiles. The molecular masses of FIV.1, FIV.2, and FIV.3 were determined, resulting in 175.99, 190.07, and 218.16 Da, respectively. Further confirmation through 1H-NMR and 13C-NMR analyses revealed that these molecules were serotonin, N-methylserotonin, and bufotenidine. These intriguing compounds are speculated to play a pivotal role in self-defense and increasing venom toxicity and could also offer promising biotechnological applications as small bioactive molecules.

Discapacidad física, una valoración bajo dos perspectivas para la inserción laboral en Perú / Physical disability, an assessment under two perspectives for labor market insertion in Peru / Deficiência física, uma avaliação sob duas perspectivas para a inserção no mercado de trabalho no Peru

Las normativas legales peruanas como es la Ley 29973, busca la promoción, protección de las personas con discapacidad en el ámbito laboral logrando así el desarrollo, igualdad e inclusión social, política que actualmente aplicado en las instituciones públicas ni privadas en Perú. Objetivo. Analizar la influencia de la discapacidad física en la inserción laboral en Perú. Materiales y Métodos. La metodología que se utilizó estuvo enmarcada en el enfoque cuantitativo, el tipo de investigación fue básica causal explicativo, el método hipotético deductivo, el diseño de la investigación fue no experimental de corte transeccional. La población fue de 61 usuarios, la técnica utilizada para la recolección de datos fue la encuesta y como instrumento el cuestionario, los datos se analizaron mediante el software estadístico SPSS. El procesamiento estadístico fue no paramétrico de Chi-Cuadrada. Resultados. Como resultado de la investigación fue que el 31,1% de los usuarios manifestaron que no están insertados en el mercado laboral ya que la discapacidad física que poseen es de tipo paraplejia, es decir, que, ambas piernas carecen de movilidad lo cual es una restricción para su desarrollo y dificulta su integración en el mercado laboral. Conclusiones. La discapacidad influye significativamente en la inserción laboral de los usuarios de la Oficina Municipal de Atención a las Personas con Discapacidad.

Peruvian legal regulations such as Law 29973, seeks the promotion and protection of people with disabilities in the workplace, thus achieving development, equality and social inclusion, a policy that is currently applied in public and private institutions in Peru. Objective. To analyze the influence of physical disability on labor market insertion in Peru. Materials and Methods. The methodology used was framed in the quantitative approach, the type of research was basic causal explanatory, the method was hypothetical deductive, the research design was non-experimental of transectional cut. The population consisted of 61 users, the technique used for data collection was the survey and the instrument was the questionnaire; the data were analyzed using SPSS statistical software. The statistical processing was nonparametric Chi-Square. Results. As a result of the research, 31.1% of the users stated that they are not inserted in the labor market since the physical disability they have is paraplegia, that is, both legs lack mobility, which is a restriction for their development and hinders their integration in the labor market. Conclusions. Disability has a significant influence on the labor market insertion of the users of the Municipal Office of Attention to People with Disabilities.

As normas legais peruanas, como a Lei 29973, buscam a promoção e a proteção de pessoas com deficiência no local de trabalho, alcançando assim o desenvolvimento, a igualdade e a inclusão social, uma política que atualmente é aplicada em instituições públicas e privadas no Peru. Objetivo. Analisar a influência da deficiência física na inserção laboral no Peru. Materiais e métodos. A metodologia utilizada foi enquadrada no enfoque quantitativo, o tipo de pesquisa foi causal explicativa básica, o método foi hipotético dedutivo, o desenho da pesquisa foi de corte transeccional não experimental. A população foi de 61 usuários, a técnica utilizada para a coleta de dados foi a pesquisa e como instrumento o questionário, os dados foram analisados com o uso do software estatístico SPSS. O processamento estatístico foi o qui-quadrado não paramétrico. Resultados. Como resultado da pesquisa, 31,1% dos usuários afirmaram que não estão inseridos no mercado de trabalho porque a deficiência física que possuem é a paraplegia, ou seja, falta mobilidade nas duas pernas, o que é uma restrição para o seu desenvolvimento e dificulta a sua integração no mercado de trabalho. Conclusões. A deficiência tem uma influência significativa na inserção no mercado de trabalho dos usuários da Secretaria Municipal de Atenção às Pessoas com Deficiência.

Antimicrobial Compounds from Skin Secretions of Species That Belong to the Bufonidae Family.

Skin secretions of toads are a complex mixture of molecules. The substances secreted comprise more than 80 different compounds that show diverse pharmacological activities. The compounds secreted through skin pores and parotid glands are of particular interest because they help toads to endure in habitats full of pathogenic microbes, i.e., bacteria, fungi, viruses, and protozoa, due to their content of components such as bufadienolides, alkaloids, and antimicrobial peptides. We carried out an extensive literature review of relevant articles published until November 2022 in ACS Publications, Google Scholar, PubMed, and ScienceDirect. It was centered on research addressing the biological characterization of the compounds identified in the species of genera Atelopus, Bufo, Duttaphrynus, Melanophryniscus, Peltopryne, Phrynoidis, Rhaebo, and Rhinella, with antibacterial, antifungal, antiviral, and antiparasitic activities; as well as studies performed with analogous compounds and skin secretions of toads that also showed these activities. This review shows that the compounds in the secretions of toads could be candidates for new drugs to treat infectious diseases or be used to develop new molecules with better properties from existing ones. Some compounds in this review showed activity against microorganisms of medical interest such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Coronavirus varieties, HIV, Trypanosoma cruzi, Leishmania chagasi, Plasmodium falciparum, and against different kinds of fungi that affect plants of economic interest.

Una revisión de alcance sobre las relaciones entre vínculos sexo-afectivos y tecnologías digitales / A Scoping Review on the Relationships Between Sexual‑Affectional Bonds and Digital Technologies

Resumen Las aplicaciones de citas son cada vez más utilizadas, sobre todo entre las personas de las generaciones millennial y centennial. En el marco de dichas apps emergen fenómenos interactivos relativos a los vínculos sexo-afectivos que ameritan ser investigados. Este artículo presenta los resultados de una revisión de alcance (scoping review) sobre investigaciones que relacionan los vínculos sexo-afectivos y el uso de tecnologías digitales, publicadas en castellano y en revistas científicas de Iberoamérica entre los años 2009 y 2019. La búsqueda se realizó en las bases de datos Dialnet, Psyarticles, Redalyc, Scielo, Science Direct, Scopus y Web of Science .WOS). Luego de aplicar los criterios de inclusión y exclusión a los 579 registros iniciales, se decantó una muestra final de 23 artículos. Los hallazgos muestran que las investigaciones se ocupan principalmente de cuatro temas: 1) los significados sobre el uso de aplicaciones de citas (dating apps); 2) los fenómenos digitales relacionados con los vínculos sexo-afectivos; 3) el sexting; y 4) la violencia entre parejas en Internet. La construcción de vínculos sexo-afectivos por medio de tecnologías digitales se vale de fenómenos psicosociales como la auto-presentación online, la desinhibición online y la comunicación asincrónica.

Abstract Dating apps are being widely used, especially among millennials and centennials. Within the framework of these applications, interactive phenomena worth research emerge related to sexual-affectional bonds. This article presents the results of a scoping review of research that establishes relationships between sexual-affectional bonds and the use of digital technologies, published in Spanish in scientific journals in Ibero-America between 2009 and 2019. The search was conducted in the Dialnet, Psyarticles, Redalyc, Scielo, Science Direct, Scopus, and Web of Science (WOS) databases. After applying the inclusion and exclusion criteria to the 579 initial records, a final sample of 23 articles was defined. Findings indicate that research focuses mainly on four topics: 1) the meanings of the use of dating apps; 2) digital phenomena related to sexual‑affectional bonds; 3) sexting; and 4) violence between couples on the Internet. The construction of sexual-affectional bonds through digital technologies makes use of psychosocial phenomena such as online self-presentation, online disinhibition, and asynchronous communication.

Determining the clinical significance of computer interpreted electrocardiography conclusions.

BACKGROUND: Computerized electrocardiogram (EKG) interpretation technology was developed in the mid-20th century, but its use continues to be controversial. This study aims to determine clinical factors which indicate greater odds of clinical significance of an abnormal computerized EKG interpretation. METHODS: The inclusion criteria for this retrospective study were patients who underwent outpatient echocardiography for the indication of an abnormal EKG and had an EKG abnormality diagnosed by the computerized EKG system. Qualifying patients had the results of their computerized EKG, echocardiogram, and charted patient characteristics collected. Computerized diagnoses and patient characteristics were assessed to determine if they were associated with increasing or decreasing the odds of an echocardiographic abnormality via logistic regression. Chi-square and t-test analyses were used for categorical and continuous variables, respectively. Odds ratios are presented as odds ratio [95% confidence interval]. A P-value of ≤ 0.05 was considered statistically significant. RESULTS: A total of 515 patients were included in this study. The population was 59% women with an average age of 57 ± 16 years, and a mean BMI of 30.1 ± 7.3 kg/m2. Patients with echocardiographic abnormalities tended to have more cardiac risk factors than patients without abnormalities. In our final odds ratio model consisting of both patient characteristics and EKG diagnoses, age, coronary disease (CAD), and diabetes mellitus (DM) increased the odds of an echocardiographic abnormality (1.04 [1.02-1.06], 2.68 [1.41-5.09], and 1.75 [1.01-3.04], respectively). That model noted low QRS voltage decreased the odds of an abnormal echocardiogram (0.31 [0.10-0.91]). CONCLUSION: Our findings suggest that in patients with an abnormal computerized EKG reading, the specific factors of older age, CAD, and DM are associated with higher odds of abnormalities on follow-up echocardiography. These results, plus practitioner overreading, can be used to determine more appropriate management when faced with an abnormal computerized EKG diagnosis.

Structural and functional characterization of NDBP-4 family antimicrobial peptides from the scorpion Mesomexovis variegatus.

Six peptides, belonging to the NDBP-4 family of scorpion antimicrobial peptides were structurally and functionally characterized. The sequence of the mature peptides VpCT1, VpCT2, VpCT3 and VpCT4 was inferred by transcriptomic analysis of the venom gland of the scorpion Mesomexovis variegatus. Analysis of their amino acid sequences revealed patterns that are also present in previously reported peptides that show differences in their hemolytic and antimicrobial activities in vitro. Two other variants, VpCT3W and VpCTConsensus were designed to evaluate the effect of sequence changes of interest on their structure and activity. The synthesized peptides were evaluated by circular dichroism to confirm their α-helical conformation in a folding promoting medium. The peptides were assayed on two Gram-positive and three Gram-negative bacterial strains, and on two yeast strains. They preferentially inhibited the growth of Staphylococcus aureus, were mostly ineffective on Pseudomonas aeruginosa, and moderately inhibited the growth of Candida yeasts. All six peptides exhibited hemolytic activity on human erythrocytes in the range of 4.8-83.7 µM. VpCT3W displayed increased hemolytic and anti-yeast activities, but showed no change in antibacterial activity, relative to its parental peptide, suggesting that Trp6 may potentiate the interaction of VpCT3 with eukaryotic cell membranes. VpCTConsensus showed broader and enhanced antimicrobial activity relative to several of the natural peptides. The results presented here contribute new information on the structure and function of NDBP-4 antimicrobial peptides and provides clues for the design of less hemolytic and more effective antimicrobial peptides.

Toxin Ct1a, from venom of Centruroides tecomanus, modifies the spontaneous firing frequency of neurons in the suprachiasmatic nucleus.

The peptide, denominated Ct1a, is a ß-toxin of 66 amino acids, isolated from venom of the scorpion, Centruroides tecomanus, collected in Colima, Mexico. This toxin was purified using size exclusion, cationic exchange, and reverse phase chromatography. It is the most abundant toxin, representing 1.7% of the soluble venom. Its molecular mass of 7588.9 Da was determined by mass spectrometry. The amino acid sequence was determined by Edman degradation and confirmed by transcriptomic analysis. Since neurons of the suprachiasmatic nucleus (SCN) maintain a spontaneous firing rate (SFR), we evaluated the physiological effects of toxin Ct1a on these neurons. The SFR exhibited a bimodal concentration-dependent response: 100 nM of Ct1a increased the SFR by 223%, whereas 500 nM and 1000 nM reduced it to 42% and 7%, respectively. Control experiments, consisting of recordings of the SFR during a time similar to that used in Ct1a testing, showed stability throughout the trials. Experiments carried out with denatured Ct1a toxin (500 nM) caused no variation in SFR recordings. Action potentials of SCN neurons, before and after Ct1a (100 nM) showed changes in the time constants of depolarization and repolarization phases, amplitude, and half-time. Finally, recordings of hNav1.6 sodium currents indicated that Ct1a shifts the channel activation to a more negative potential and reduces the amplitude of the peak current. These results all demonstrate that toxin Ct1a affects the SFR of SCN neurons by acting upon sodium channels of sub-type 1.6, implicating them in regulation of the SFR of SCN neurons.

Venom gland transcriptome from Heloderma horridum horridum by high-throughput sequencing.

Lizards of the Helodermatidae (Anguimorpha) family consist of at least two well recognized species: Heloderma horridum horridum and Heloderma suspectum suspectum. They contain specialized glands in their jaws that produce venomous secretions that causes envenoming symptoms to bitten animals. One way to study proteins from such secretions is by RNA-seq; a powerful molecular tool to characterize the transcriptome of such specialized gland, and its protein secretions. The total RNA from venom gland tissues of H. horridum horridum was extracted and a cDNA library was constructed and sequenced. Overall, 114,172 transcripts were found, and 199 were annotated based on sequence similarities to previously described peptides/proteins. Transcripts coding for putative exendins, defensins, natriuretics and serine protease inhibitors were the most highly expressed. Transcripts that code for several putative serine proteases, phospholipases, metalloproteases, lipases, L-amino oxidase and nucleases were also found. Some of the novel identified transcripts were translationally controlled tumor proteins, venom factors, vespryns, waprins, lectins, cystatins and serine protease inhibitors. All these new protein structures may contribute to a better understanding of the venomous secretions of the Helodermatidae family.

Transcriptomic and proteomic analyses of the venom and venom glands of Centruroides hirsutipalpus, a dangerous scorpion from Mexico.

Centruroides hirsutipalpus (Scorpiones: Buthidae) is related to the "striped scorpion" group inhabiting the western Pacific region of Mexico. Human accidents caused by this species are medically important due to the great number of people stung and the severity of the resulting intoxication. This communication reports an extensive venom characterization using high-throughput proteomic and Illumina transcriptomic sequencing performed with RNA purified from its venom glands. 2,553,529 reads were assembled into 44,579 transcripts. From these transcripts, 23,880 were successfully annoted using Trinotate. Using specialized databases and by performing bioinformatic searches, it was possible to identify 147 putative venom protein transcripts. These include α- and ß-type sodium channel toxins (NaScTx), potassium channel toxins (KScTx) (α-, ß-, δ-, γ- and λ-types), enzymes (metalloproteases, hyaluronidases, phospholipases, serine proteases, and monooxygenases), protease inhibitors, host defense peptides (HDPs) such as defensins, non-disulfide bridge peptides (NDBPs), anionic peptides, superfamily CAP proteins, insulin growth factor-binding proteins (IGFBPs), orphan peptides, and other venom components (La1 peptides). De novo tandem mass spectrometric sequencing of digested venom identificatied 50 peptides. The venom of C. hirsutipalpus contains the highest reported number (77) of transcripts encoding NaScTxs, which are the components responsible for human fatalities.

Multiple-parameter screening and prevention of preeclampsia: evaluation of a protocol implemented at Hospital Universitario Puerta de Hierro / Cribado multiparamétrico y prevención de la preeclampsia. Evaluación del protocolo implantado en el Hospital Universitario Puerta de Hierro

Objective: To evaluate the implementation in our center of a preeclampsia risk screening protocol in a low-risk population combined with preventive treatment (aspirin, 100 mg/d) by evaluating the variation in the incidence of preeclampsia. To validate the analysis tool and its predictive strength. Material and methods: We studied 310 patients divided into 2 groups: 138 controls (TR) and 172 patients who had undergone screening and received preventive treatment (CI). We collected demographic data, gestational age at consultation, obstetric history, reproductive method, risk factors for preeclampsia (hypertension, diabetes, BMI, kidney disease, and coagulopathy), use of aspirin as preventive therapy, and data on the outcome of pregnancy (hypertension, proteinuria, diagnosis of preeclampsia, and complications). In the CI group, we also recorded the risk of preeclampsia. This was calculated retrospectively in the TR group. Results: The protocol had 80% sensitivity and 98.4% specificity. The incidence of preeclampsia was 3.62% in the TR group and 0.58% in the CI group (p=0.053), with an OR of 0.155 (0.017-1.34). Among patients with a high risk, 66.7% developed preeclampsia in the TR group and 9.1% in the CI group (p=0.027), with an OR of 0.05 (0.04-0.57) and a number needed to treat of 1.74. Conclusions: The high sensitivity and specificity of the analytical tool make it adequate for screening. The protocol reduces the incidence of preeclampsia in high-risk patients, even if that difference was not significant at the level of the study population

Objetivo: evaluar la implantación, en nuestro centro, de un protocolo de cribado del riesgo de preeclampsia en población de bajo riesgo obstétrico, combinado con tratamiento preventivo con 100 mg diarios de ácido-acetilsalicílico, mediante el análisis de la variación de la incidencia de preeclampsia. Validar la herramienta utilizada, analizando su capacidad predictiva. Material y métodos: se estudiaron 310 pacientes, distribuidas en dos grupos: 138 controles (TR) y 172 con cribado y tratamiento preventivo (CI). Se recogieron datos demográficos, edad gestacional en consulta, historia obstétrica, método reproductivo, factores de riesgo de preeclampsia (hipertensión, diabetes, IMC, nefropatía y coagulopatía), toma de ácido-acetilsalicílico de forma preventiva y datos del final de la gestación (hipertensión, proteinuria, diagnóstico de pree-clampsia y complicaciones). En el grupo CI se recogió el índice de riesgo, y en el grupo TR se calculó de forma retrospectiva. Resultados: la herramienta obtuvo una sensibilidad del 80% y una especificidad del 98,4%. La incidencia de preeclamp-sia resultó del 3,62% en el grupo TR frente al 0,58% en el grupo CI (p=0,053), con una OR de 0,155 [0,017-1,34]. Entre las pacientes con índice de alto riesgo, un 66,7% del grupo TR presentó preeclampsia, frente a un 9,1% del grupo CI (p=0,027), con OR 0,05 [0,04-0,57] y una NNT de 1,74. Conclusiones: la herramienta utilizada tiene elevada sensibilidad y especificidad, resultando útil como cribado. El protocolo implantado reduce la incidencia de preeclampsia en pacientes con índice de alto riesgo, aunque la variación a nivel poblacional no fue significativa

Transcriptomic and Proteomic Analyses Reveal the Diversity of Venom Components from the Vaejovid Scorpion Serradigitus gertschi.

To understand the diversity of scorpion venom, RNA from venomous glands from a sawfinger scorpion, Serradigitus gertschi, of the family Vaejovidae, was extracted and used for transcriptomic analysis. A total of 84,835 transcripts were assembled after Illumina sequencing. From those, 119 transcripts were annotated and found to putatively code for peptides or proteins that share sequence similarities with the previously reported venom components of other species. In accordance with sequence similarity, the transcripts were classified as potentially coding for 37 ion channel toxins; 17 host defense peptides; 28 enzymes, including phospholipases, hyaluronidases, metalloproteases, and serine proteases; nine protease inhibitor-like peptides; 10 peptides of the cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 protein superfamily; seven La1-like peptides; and 11 sequences classified as "other venom components". A mass fingerprint performed by mass spectrometry identified 204 components with molecular masses varying from 444.26 Da to 12,432.80 Da, plus several higher molecular weight proteins whose precise masses were not determined. The LC-MS/MS analysis of a tryptic digestion of the soluble venom resulted in the de novo determination of 16,840 peptide sequences, 24 of which matched sequences predicted from the translated transcriptome. The database presented here increases our general knowledge of the biodiversity of venom components from neglected non-buthid scorpions.

Kv1.3 channel blockade with the Vm24 scorpion toxin attenuates the CD4+ effector memory T cell response to TCR stimulation.

BACKGROUND: In T cells, the Kv1.3 and the KCa3.1 potassium channels regulate the membrane potential and calcium homeostasis. Notably, during TEM cell activation, the number of Kv1.3 channels on the cell membrane dramatically increases. Kv1.3 blockade results in inhibition of Ca2+ signaling in TEM cells, thus eliciting an immunomodulatory effect. Among the naturally occurring peptides, the Vm24 toxin from the Mexican scorpion Vaejovis mexicanus is the most potent and selective Kv1.3 channel blocker known, which makes it a promissory candidate for its use in the clinic. We have shown that addition of Vm24 to TCR-activated human T cells inhibits CD25 expression, cell proliferation and reduces delayed-type hypersensitivity reactions in a chronic inflammation model. Here, we used the Vm24 toxin as a tool to investigate the molecular events that follow Kv1.3 blockade specifically on human CD4+ TEM cells as they are actively involved in inflammation and are key mediators of autoimmune diseases. METHODS: We combined cell viability, activation, and multiplex cytokine assays with a proteomic analysis to identify the biological processes affected by Kv1.3 blockade on healthy donors CD4+ TEM cells, following TCR activation in the presence or absence of the Vm24 toxin. RESULTS: The peptide completely blocked Kv1.3 channels currents without impairing TEM cell viability, and in response to TCR stimulation, it inhibited the expression of the activation markers CD25 and CD40L (but not that of CD69), as well as the secretion of the pro-inflammatory cytokines IFN-γ and TNF and the anti-inflammatory cytokines IL-4, IL-5, IL-9, IL-10, and IL-13. These results, in combination with data from the proteomic analysis, indicate that the biological processes most affected by the blockade of Kv1.3 channels in a T cell activation context were cytokine-cytokine receptor interaction, mRNA processing via spliceosome, response to unfolded proteins and intracellular vesicle transport, targeting the cell protein synthesis machinery. CONCLUSIONS: The Vm24 toxin, a highly specific inhibitor of Kv1.3 channels allowed us to define downstream functions of the Kv1.3 channels in human CD4+ TEM lymphocytes. Blocking Kv1.3 channels profoundly affects the mRNA synthesis machinery, the unfolded protein response and the intracellular vesicle transport, impairing the synthesis and secretion of cytokines in response to TCR engagement, underscoring the role of Kv1.3 channels in regulating TEM lymphocyte function.

An Alkaloid from Scorpion Venom: Chemical Structure and Synthesis.

While most scorpion venom components identified in the past are peptidic or proteinic in nature, we report here a new alkaloid isolated from the venom of the Mexican scorpion Megacormus gertschi. Nuclear magnetic resonance and mass spectrometric investigations elucidate the structure of the alkaloid as ( Z)- N-(2-(1 H-imidazol-4-yl)ethyl)-3-(4-hydroxy-3-methoxyphenyl)-2-methoxyacrylamide (1). A chemical method of synthesizing this alkaloid is also described. Although abundant in venom, the above alkaloid was not found to have insecticidal activity. Structural analysis suggests that this venom alkaloid might be of potential interest for evaluating its medicinal effect.

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.

Arthropod toxins acting on neuronal potassium channels.

Arthropod venoms are a rich mixture of biologically active compounds exerting different physiological actions across diverse phyla and affecting multiple organ systems including the central nervous system. Venom compounds can inhibit or activate ion channels, receptors and transporters with high specificity and affinity providing essential insights into ion channel function. In this review, we focus on arthropod toxins (scorpions, spiders, bees and centipedes) acting on neuronal potassium channels. A brief description of the K+ channels classification and structure is included and a compendium of neuronal K+ channels and the arthropod toxins that modify them have been listed. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.'

Comparative proteomic analysis of female and male venoms from the Mexican scorpion Centruroides limpidus: Novel components found.

Venom from male and female scorpions of the species Centruroides limpidus were separated by HPLC and their molecular masses determined by mass spectrometry. The relative concentration of components eluting in equivalent retention times from the HPLC column shows some differences. A new peptide with 29 amino acids, cross-linked by three disulfide bonds was found in male scorpions and its structure determined. Another unknown peptide present in female venom, with sequence identity similar to K+-channel blocking peptide was isolated. This peptide contains 39 amino acid residues linked by three disulfide bonds. Due to sequence similarities, a systematic number (αKTx2.18) was assigned. Venom from male and female scorpions was separated by Sephadex G-50 gel filtration. Components of fraction I of this chromatogram were analyzed by two-dimensional gel electrophoresis and 41 spots were selected (20 from female and 21 from male). The spots were excised from the gel, enzymatically digested and sequenced by LC-MS/MS. This procedure allowed the identification of several proteins containing similar amino acid sequence of other known proteins registered on UniProt database. Among these proteins the presence of metalloproteinases (proteolytic enzymes), hyaluronidases and phosphatases were experimentally determined and shown to be present in both venom samples. The results shown here should help further work aimed at fully identification of the structure and function of venom components form C. limpidus male and female scorpions.

Peptides from the scorpion Vaejovis punctatus with broad antimicrobial activity.

The antimicrobial potential of two new non-disulfide bound peptides, named VpAmp1.0 (LPFFLLSLIPSAISAIKKI, amidated) and VpAmp2.0 (FWGFLGKLAMKAVPSLIGGNKSSSK) is here reported. These are 19- and 25-aminoacid-long peptides with +2 and +4 net charges, respectively. Their sequences correspond to the predicted mature regions from longer precursors, putatively encoded by cDNAs derived from the venom glands of the Mexican scorpion Vaejovis punctatus. Both peptides were chemically synthesized and assayed against a variety of microorganisms, including pathogenic strains from clinical isolates and strains resistant to conventional antibiotics. Two shorter variants, named VpAmp1.1 (FFLLSLIPSAISAIKKI, amidated) and VpAmp2.1 (FWGFLGKLAMKAVPSLIGGNKK), were also synthesized and tested. The antimicrobial assays revealed that the four synthetic peptides effectively inhibit the growth of both Gram-positive (Staphylococcus aureus and Streptococcus agalactiaea) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, with MICs in the range of 2.5-24.0 µM; yeasts (Candida albicans and Candida glabrata) with MICs of 3.1-50.0 µM; and two clinically isolated strains of Mycobacterium tuberculosis-including a multi-drug resistant one- with MICs in the range of 4.8-30.5 µM. A comparison between the activities of the original peptides and their derivatives gives insight into the structural/functional role of their distinctive residues.