Vinte espécies de invertebrados marinhos, coletados na costa brasileira, foram avaliados quanto à presença de atividade hemaglutinante/hemolítica. Em pelo menos doze espécies testadas, a atividade hemaglutinante foi diferencial para diferentes grupos sanguíneos, sugerindo a presença de lectinas. Extratos de quatro espécies apresentaram atividade hemolítica. Duas novas lectinas foram purificadas da esponja marinha Cliona varians (CvL-2) e do pepino-domar Holothuria grisea (HGL). CvL-2 foi capaz de aglutinar eritrócitos de coelho e foi inibida por galactosídeos. A atividade hemaglutinante foi estável em pH neutro e temperaturas abaixo de 70 °C. CvL-2 é uma proteína trímero com subunidades de 175 kDa. Por outro lado, HGL apresentou atividade hemaglutinante e hemolítica em eritrócitos humanos e de coelho, mas a hemólise pôde ser inibida por proteção osmótica, enquanto que a aglutinação foi inibida por mucina. HGL mostrou-se estável em valores de pH de 4-10 e temperaturas até 90 °C. Em eletroforeses e gel filtração, HGL foi uma proteína monômero de 15 kDa. CvL-2 e HGL mostraram diferentes níveis de toxicidade contra náuplios de Artemia. CvL-2 apresentou LC50 de 850,1 μg/mL, enquanto que HGL apresentou LC50 de 9,5 μg/mL.

Twenty species of marine invertebrates from the Brazilian coast were screened for hemagglutinating/hemolytic activity. In at least twelve tested species, hemagglutinating activity was different for different blood types, suggesting the presence of lectins. Extracts from four species showed hemolytic activity. Two new lectins were purified from the marine sponge Cliona varians (CvL-2) and sea cucumber Holothuria grisea (HGL). CvL-2 was able to agglutinate rabbit erythrocytes and was inhibited by galactosides. The hemagglutinating activity was optimal in pH neutral and temperatures below 70 °C. CvL-2 is a trimeric protein with subunits of 175 kDa. On the other hand, HGL showed both hemagglutinating and hemolytic activity in human and rabbit erythrocytes, but hemolysis could be inhibited by osmotic protection, and agglutination was inhibited by mucin. HGL was stable in pH values ranging from 4 to 10 and temperatures up to 90 °C. In electrophoresis and gel filtration, HGL was a monomeric protein with 15 kDa. CvL-2 and HGL showed different levels of toxicity to Artemia naplii. CvL-2 showed LC50 of 850.1 μg/mL, whereas HGL showed LC50 of 9.5 µg/mL.

Gastric cancer (GC) is a multifactorial disease with a high mortality rate in Brazil and worldwide. This work aimed to evaluate single nucleotide polymorphisms (SNP) rs1695, in the Glutathione S-Transferase Pi (GSTP1) gene in GC samples by comparative analysis Specific PCR - ASP and Dideoxy Single Allele-Specific PCR - DSASP methods. The DSASP is the proposed new method for allelic discrimination. This work analyzed 60 GC samples, 26 diffuse and 34 intestinal types. The SNP rs1695 of the GSTP1 gene was significantly associated with GC analyzed by DSASP method (χ2 = 9.7, P < 0.05). A comparative analysis of the data obtained from both methods did not differ significantly (χ2 = 0.08, P > 0.05). These results suggest that the SNP rs1695 of the GSTP1 gene was a risk factor associated with gastric carcinogens is and the DSASP method was a new successfully low-cost strategy to study allelic discrimination.

O presente trabalho relata nossa experiência relacionada à cristalização de quatro hemoglobinas de peixe de três espécies brasileiras de Teleostes: Liposarcus anisitsi, Brycon cephalus e Piaractus mesopotamicus. Os dados, aqui apresentados, são parte de um estudo funcional e estrutural sistemático de hemoglobinas de peixe com o objetivo de melhor entender a ampla faixa de propriedades funcionais e estruturais exibidas por estas proteínas. Nós também apresentamos um método otimizado para cristalização de hemoglobinas de peixes, que pode reduzir a quantidade de hemoglobina inicialmente usada nos experimentos de cristalização.

The present work reports our succesfull experience concerning crystallization of four fish hemoglobins from three Brazilian species of Teleosts: Liposarcus anisitsi, Brycon cephalus and Piaractus mesopotamicus. The data shown here is part of a systematic functional and structural study of fish hemoglobins with the aim of better understanding the outstanding range of functional and structural properties exhibited by these proteins. We also present a reduced sparse-matrix method for crystallization of fish hemoglobins, which can reduce the amount of hemoglobin initially used in the crystallization experiments.