Structural characterization of a galectin isolated from the marine sponge Chondrilla caribensis with leishmanicidal potential.

BACKGROUND: Solving primary structure of lectins leads to an understanding of the physiological roles within an organism and its biotechnological potential. Only eight sponge lectins have had their primary structure fully determined. METHODS: The primary structure of CCL, Chondrilla caribensis lectin, was determined by tandem mass spectrometry. The three-dimensional structure was predicted and the protein-carbohydrate interaction analysed by molecular docking. Furthermore, the anti-leishmanial activity was observed by assays with Leishmania infantum. RESULTS: The amino acid sequence consists of 142 amino acids with a calculated molecular mass of 15,443 Da. The lectin has a galectin-like domain architecture. As observed in other sponge galectins, the signature sequence of a highly conserved domain was also identified in CCL with some modifications. CCL exhibits a typical galectin structure consisting of a ß-sandwich. Molecular docking showed that the amino acids interacting with CCL ligands at the monosaccharide binding site are mostly the same as those conserved in this family of lectins. Through its interaction with L. infantum glycans, CCL was able to inhibit the development of this parasite. CCL also induced apoptosis after eliciting ROS production and altering the membrane integrity of Leishmania infantum promastigote. CONCLUSIONS: CCL joins the restricted group of sponge lectins with determined primary structure and very high biotechnological potential owing to its promising results against pathogens that cause Leishmaniasis. GENERAL SIGNIFICANCE: As the determination of primary structure is important for biological studies, now CCL can become a sponge galectin with an exciting future in the field of human health.

Structural characterization of two isolectins from the marine red alga Solieria filiformis (Kützing) P.W. Gabrielson and their anticancer effect on MCF-7 breast cancer cells.

As described in the literature, Solieria filiformis lectin (SfL) from the marine red alga S. filiformis was found to have antinociceptive and anti-inflammatory effects. In this study, we characterized two SfL variants, SfL-1 and SfL-2, with molecular mass of 27,552Da and 27,985Da, respectively. The primary structures of SfL-1 and SfL-2 consist of four tandem-repeat protein domains with 67 amino acids each. SfL-1 and -2 showed high similarity to OAAH-family lectins. 3D structure prediction revealed that SfL-1 and -2 are composed of two ß-barrel-like domains formed by five antiparallel ß-strands, which are connected by a short peptide linker. Furthermore, the mixture of isoforms (SfLs) showed anticancer effect against MCF-7 cells. Specifically, SfLs inhibited 50% of viability in MCF-7 cells after treatment at 125µg.mL-1, while the inhibition of Human Dermal Fibroblasts (HDF) was 34% with the same treatment. Finally, 24h after treatment, 25% of MCF-7 cells were in early apoptosis and 35% in late apoptosis. Evaluation of pro- and anti-apoptotic gene expression of MCF-7 cells revealed that SfLs induced caspase-dependent apoptosis within 24h.

Fungal biodiversity of air in hospitals in the city of Fortaleza, Ceará, Brazil / Biodiversidade fúngica do ar de hospitais da cidade de Fortaleza, Ceará, Brasil

Objectives: To monitor the environment in specific areas of three tertiary hospitals in Fortaleza - CE, seeking to report the presence of potentially pathogenic fungi for patients and staff, contributing to a better risk assessment in these hospitals. Methods: In the period from December, 2005 to November, 2006, air samples from three public hospitals were collected monthly, which resulted in 180 air samples originated in 15 hospitals. The biological specimens were collected using the passive method of sedimentation, with exposure of Petri dishes containing Sabouraud agar supplemented with antibiotic. The dishes were incubated for 10 days (28°C) and all fungal colonies developed were subsequently identified. Results: 10,608 colonies were isolated, belonging to 16 genera, the most common being Aspergillus, Penicillium, Candida, Curvularia and Trichoderma. There were no statistically significant relationships between the total number of colonies and the characteristics of each environment studied, except for three of those. Conclusion: The difference in fungal concentrations in the air of these hospitals is possibly more related to instability of human activities, such as overpopulated settings and construction works, than to climatic variations observed in the period.

Objetivos: Monitorar o ambiente em áreas específicas de três hospitais terciários da cidade de Fortaleza ? CE, buscando relatar a presença de fungos potencialmente patogênicos para pacientes e funcionários, contribuindo para uma melhor avaliação de riscos nesses hospitais. Métodos: No período de dezembro/2005 a novembro/2006, foram realizadas coletas mensais de amostras do ar de três hospitais públicos, que resultaram em 180 amostras de ar oriundas de 15 ambientes hospitalares. Os espécimes biológicos foram coletados através do método da sedimentação passiva, com exposições de placas de Petri, contendo ágar Sabouraud, suplementado com antibiótico. As placas foram incubadas por 10 dias (28°C), com a posterior identificação de todas as colônias fúngicas desenvolvidas. Resultados: Isolaram-se 10.608 colônias, pertencentes a 16 gêneros, sendo os mais frequentes Aspergillus, Penicillium, Candida, Curvularia e Trichoderma. Não se observaram relações estatisticamente significativas entre o número total de colônias e as características de cada ambiente analisado, com exceção de três ambientes. Conclusão: A diferença na concentração fúngica do ar desses hospitais possivelmente está mais relacionada com desequilíbrios das atividades humanas, tais como ambientes superpovoados e obras de construção, do que com as variações climáticas observadas no período em análise.