Staining tumor cells with biotinylated ACL-I, a lectin isolated from the marine sponge, Axinella corrugata.

Axinella corrugata lectin 1 (ACL-1) was purified from aqueous extracts of the marine sponge, Axinella corrugata. ACL-1 strongly agglutinates native rabbit erythrocytes. The hemagglutination is inhibited by N-acetyl derivatives, particularly N, N', N"-triacetylchitotriose, N-acetyl-D-glucosamine, N-acetyl-D-mannosamine and N-acetyl-D-galactosamine. We investigated the capacity of biotinylated ACL-1 to stain several transformed cell lines including breast (T-47D, MCF7), colon (HT-29), lung (H460), ovary (OVCAR-3) and bladder (T24). ACL-I may bind to both monosaccharides and oligosaccharides of tumor cells, N-acetyl-D-galactosamine, and N-acetyl-D- glucosamine glycan types. The lectins are useful, not only as markers and diagnostic parameters, but also for tissue mapping in suspicious neoplasms. In addition, they provide a better understanding of neoplasms at the cytological and molecular levels. Furthermore, the use of potential metastatic markers such as lectins is crucial for developing successful tools for therapy against cancer. We observed that biotinylated ACL-I stains tumor cells and may hold potential as a probe for identifying transformed cells and for studying glycan structures synthesized by such cells.

Detecção de atividade lectínica e atividade hemolítica em extratos de esponjas (Porifera) nativas da costa atlântica do Brasil / Detection of lectinic activity and hemolytic activity in extracts of native sponges (Porifera) of atlantic coast of Brazil

Extratos aquosos de vinte espécies de esponjas da costa Atlântica brasileira foram testados para verificação da presença de atividade lectínica e atividade hemolítica. Hemaglutinação para eritrócitos humanos e de distintos animais foi evidenciada em 12 dos 20 extratos testados. Os extratos das espécies Axinella corrugata, Chondrilla nucula, Chondrosia collectrix, Cinachyrella alloclada e Guitarra sp1. foram os que apresentaram maior atividade hemaglutinante. Dos doze extratos com atividade hemaglutinante dez tiveram a atividade inibida por um ou mais açúcares e/ou glicoproteínas. A lectina do extrato de Chondrilla nucula foi resistente à desnaturação térmica quando aquecida a 100 ºC por 60 minutos. Atividade hemolítica foi encontrada apenas nos extratos de Petromica citrina e Acervochalina sp. As espécies que apresentaram maior potencial para futuros estudos de suas lectinas foram Axinella corrugata, Chondrilla nucula e Chondrosia collectrix, em vista da maior atividade hemaglutinante apresentada por seus extratos, aliada à maior atividade específica.

Aqueous extracts of twenty species of sea sponges of the Brazilian Atlantic coast were tested with the aim of searching the presence of lectinic and hemolytic activity. Hemagglutinating activity for human erythrocytes and for distinct animals were found in 12 of the 20 tested extracts. The extracts of Axinella corrugata, Chondrilla nucula, Chondrosia collectrix, Cinachyrella alloclada and Guitarra sp1. were the ones that presented highest hemagglutinating activity. Ten of the 12 hemagglutinating extracts had the activity inhibited by one or more sugars or glycoproteins. The lectin from Chondrilla nucula was resistant to thermal denaturation when heated up to 100 ºC for 60 minutes. Hemolytic activity was only found in the extracts from Petromica citrina and Acervochalina sp. The species of sea sponges that showed major potential for futures studies of their lectins were Axinella corrugata, Chondrilla nucula and Chondrosia collectrix, due to the highest hemagglutinating activity presented by their extracts, allied to the highest specific activity.

Neutrophil migration and aggregation induced by euphorbin, a lectin from the latex of Euphorbia milii, var. milii.

OBJECTIVE AND DESIGN: To study the neutrophil migration and aggregation induced by euphorbin, a D-galactose binding lectin from Euphorbia milii var. milli latex. MATERIALS AND METHODS: Euphorbin-induced neutrophil migration was evaluated in vivo and in vitro, in the absence or presence of soluble D-galactose. Neutrophil aggregation induced in vitro by euphorbin was determined by light microscopy. RESULTS: The neutrophil migration inducing activity of euphorbin was dose-dependent and inhibited by soluble D-galactose. Neutrophil aggregation was rapidly reversed when provoked by 0.1 mg/ml euphorbin. In higher concentrations, euphorbin caused persistent and more extensive neutrophil aggregation. CONCLUSIONS: Euphorbin induced neutrophil migration through its sugar recognition property. The transitory neutrophil aggregation, induced by a euphorbin quantity similar to that able to cause maximal chemotactic response, is characteristic of homotypic neutrophil adhesion, whereas persistent aggregation, provoked by higher euphorbin quantities, corresponds to cell agglutination by a multivalent lectin.

Polyacrylamide gel electrophoretic studies on the self-association of crotamine: characterization and molecular dimension of n-mer species.

Polyacrylamide gel electrophoresis (PAGE) at pH 4.4 was used to study the concentration dependence of absolute mobility of crotamine. Within amounts ranging from 5-65 micrograms the toxin appeared in at least three n-mer species which were characterized by their geometrical mean radius R and molecular weight Mr estimation. The R and Mr values of crotamine bands were obtained from equations described in the literature and by using standard polypeptides and proteins submitted to the same experimental conditions. When amounts of up to 20 micrograms were assayed by PAGE the bands had a monomer molecular weight value of 4650 and R was 1.08 nm. From 20-35 micrograms the toxin migrated as dimer (Mr 10,000) with an R value of 1.42 nm. However, amounts higher than 35 micrograms crotamine were mostly resolved in a "two-band" pattern with R and Mr values corresponding to higher associated species.