Microbial infections represent a problem of great importance at the public health level, with a high rate of morbidity-mortality worldwide. However, treating the different diseases generated by microorganisms requires a gradual increase in acquired resistance when applying or using them against various antibiotic therapies. Resistance is caused by various molecular mechanisms of microorganisms, thus reducing their effectiveness. Consequently, there is a need to search for new opportunities through natural sources with antimicrobial activity. One alternative is using peptides present in different scorpion venoms, specifically from the Buthidae family. Different peptides with biological activity in microorganisms have been characterized as preventing their growth or inhibiting their replication. Therefore, they represent an alternative to be used in the design and development of new-generation antimicrobial drugs in different types of microorganisms, such as bacteria, fungi, viruses, and parasites. Essential aspects for its disclosure, as shown in this review, are the studies carried out on different types of peptides in scorpion venoms with activity against pathogenic microorganisms, highlighting their high therapeutic potential.

Lectins are an important group of proteins which are spread in all kingdoms of life. Their most lighted characteristic is associated to their specific carbohydrate binding, although function has been not even identified. According to their carbohydrate specificity, several biological activities have been assessed, finding that lectins can be used as mitogenic agents, biomarkers, and cytotoxic and insecticide proteins. Lectins have been classified according to several features such as structure, source, and carbohydrate recognition. The Protein Research Group (PRG) has worked on Colombian seeds from the family of Fabaceae and Lamiaceae plants, isolating and characterizing their lectins, and found more than one lectin in some plants, indicating that according to its specificity, different lectins can have different biological activities. In the case of legume domain lectins, they have shown the biggest potential as insecticide or insectistatic agents due to the glycosylation pattern in insect midgut cells. This review attempts to identify the characteristics of plant legume lectin domains that determine their insecticidal and insectistatic activities.

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Background: The GluN2B subunit of the N-methyl-d-aspartate receptor (NMDAr) modulates many physiological processes including learning, memory, and pain. Excessive increase in NMDAr/GluN2B activity has been associated with various disorders such neuropathic pain and neuronal death following hypoxia. Thus there is an interest in identifying NMDAr antagonists that interact specifically with the GluN2B subunit. Recently based on structural analysis between the GluN2B subunit and conantokin-G, a toxin that interacts selectively with the GluN2B subunit, we designed various peptides that are predicted to act as NMDAr antagonists by interacting with the GluN2B subunit. In this study we tested this prediction for two of these peptides EAR16 and EAR18. Results:The effects of EAR16 and EAR18 in NMDA-evoked currents were measured in cultured rat embryonic hippocampal neurons and in HEK-293 cells expressing recombinant NMDAr comprised of GluN1a-GluN2A or GluN1a-GluN2B subunits. In hippocampal neurons, EAR16 and EAR18 reduced the NMDA-evoked calcium currents in a dosedependent and reversible manner with comparable IC50 (half maximal inhibitory concentration) values of 241 and 176 µM, respectively. At 500 µM, EAR16 blocked more strongly the NMDA-evoked currents mediated by the GluN1a-GluN2B (84%) than those mediated by the GluN1a-GluN2A (50%) subunits. At 500 µM, EAR18 blocked to a similar extent the NMDA-evoked currents mediated by the GluN1a-GluN2B (62%) and the GluN1a-GluN2A (55%) subunits. Conclusions:The newly designed EAR16 and EAR18 peptides were shown to block in reversible manner NMDAevoked currents, and EAR16 showed a stronger selectivity for GluN2B than for GluN2A.

RESUMENEsta revisión busca identificar las características de las lectinas vegetales con dominio de leguminosa que determinan su actividad insectistática e insecticida. Se realizó una búsqueda sistemática de literatura en las bases de datos Medline, Science Direct (Elsevier), Pubmed, Lilacs, SCOPUS, Web of Science (ISI) con el uso de palabras claves relevantes. La información recolectada fue clasificada y seleccionada en términos de su calidad y relevancia. La revisión tomó como base la información de las lectinas de Phaseolus vulgaris (PHA), Glechoma hederacea (Gleheda), Canavalia ensiformis (Concanavalina A), Griffonia simplicifolia (GSII) y Pisum sativum (PSA) y lectinas de leguminosas estudiadas en Colombia por el Grupo de Investigación en Proteínas. Se evidenció que las lectinas vegetales con dominio de leguminosa poseen rasgos estructurales caracterizados por un alto porcentaje de láminas beta asociados en estructuras diméricas o tetraméricas y que presentan varios sitios de reconocimiento a azúcares específicos, entre los cuales se destaca la manosa. Adicional a estas características, estas lectinas pueden interactuar con el sistema digestivo de insectos plaga y generar una disminución en su capacidad de absorción intestinal. Como conclusión, se puede señalar que es insuficiente la información sobre las señales que se activan y los efectos deletéreos de las lectinas con dominio de leguminosa sobre los insectos.Palabras clave: insectistático, insecticida, leguminosa, lectina. ABSTRACTThis review aims to identify the characteristics of legume lectins that determine their insecticidal and insectistatic activities. A systematic review of the literature was conducted in Medline, Science Direct (Elsevier), Pubmed, SCOPUS, Web of Science (ISI) and Lilacs databases by using relevant keywords. The information collected was classified and selected in terms of quality and relevance. This review is mainly based on information of Phaseolus vulgaris (PHA), Glechoma hederacea (Gleheda), Canavalia ensiformis (ConA), Griffonia simplicifolia (GSII) and Pisum sativum (PSA) lectins and other legume lectins studied by the Protein Research Group in Colombia. It was evidenced that legume lectins have structural features characterized by a high percentage of beta sheet structures that form dimeric or tetrameric assemblies and present several specific sugars recognition sites, 157-169. Recibido: 31 julio 2015.Aceptado: 05 febrero 2016