Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T22:52:54Z No. of bitstreams: 1 AntonioMoreiraMarquesNeto_DISSERT.pdf: 1777931 bytes, checksum: f46a9d1741f7574f2fd804826fb17637 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-24T19:13:59Z (GMT) No. of bitstreams: 1 AntonioMoreiraMarquesNeto_DISSERT.pdf: 1777931 bytes, checksum: f46a9d1741f7574f2fd804826fb17637 (MD5) / Made available in DSpace on 2017-03-24T19:13:59Z (GMT). No. of bitstreams: 1 AntonioMoreiraMarquesNeto_DISSERT.pdf: 1777931 bytes, checksum: f46a9d1741f7574f2fd804826fb17637 (MD5) Previous issue date: 2015-02-02 / Uma lectina com elevada atividade aglutinante sobre hem?cias humanas dos v?rios tipos do sistema ABO foi purificada da esponja marinha Aplysina sp. por extra??o hidroalco?lica e uma sequ?ncia de etapas de purifica??o envolvendo cromatografias de gel filtra??o em Superdex 75 10/300 GL e de troca-i?nica Resource Q (FPLC-AKTA Purifier). Ap?s purificada, a lectina denominada AplyL-1, apresentou uma ?nica cadeia pept?dica com uma massa molecular de 40 kDa e com especificidade de liga??o para D-galactose, D-galactosamina e lactose. A atividade hemaglutinante de AplyL-1 foi independente da presen?a de ?ons bivalentes e n?o foi alterada em condi??es b?sicas (acima de pH 7,0), mas bastante reduzida quando submetida a condi??es ?cidas (abaixo de pH 6,0). Testes de termoestabilidade mostraram que AplyL-1 perde gradativamente sua atividade hemaglutinante a partir de 40?C e n?o mais exibe atividade em 100?C. Aply-L1 (10 ?g/mL) foi testada frente a diversas linhagens tumorais, onde apresentou atividade citot?xica significativa para a linhagem de adenocarcinoma cervical humano (HeLa). Para a linhagem de c?lula normal 3T3 n?o foi vista atividade citot?xica. Em testes realizados com Leishmania braziliensis e Leishmania amazonensis, Aply-L1 exibiu a capacidade de aglutinar a esp?cie L. amazonensis (concentra??o de 77,5 ?g/mL). Os resultados mostram que esta nova lectina ligante de derivados de galactose pode ser importante no desenvolvimento de produtos com import?ncia biotecnol?gica e filogen?tica. / A lectin with high binding activity under human erythrocytes of different types of ABO system was isolated from the marine sponge Aplysina sp. by hydroalcoholic extraction and a sequence of purification steps involving gel filtration chromatography on Superdex 75 10/300 GL and ion exchange chromatography on Resource Q (FPLC-AKTA Purifier). Once purified, the lectin, named AplyL-1, showed a single peptide chain with a molecular of weight 40 kDa and binding specificity for D-galactose, D-galactosamine and lactose. The AplyL1 hemagglutinating activity was independent of bivalent ions and was not changed in basic conditions (pH > 7.0), but significantly reduced when submitted into acid conditions (pH <7.0). Thermal stability tests showed that AplyL-1 gradually loses its hemagglutinating activity at 40 ?C and no longer displays any activity at 100 ?C. AplyL-1 has been tested against several tumour cell lines, and howed significantly cytotoxic activity (up to 10 ?g/mL) only for human cervical adenocarcinoma cell line (HeLa). For the 3T3 normal cell line no cytotoxic activity was seen. In tests performed with Leishmania braziliensis and Leishmania amazonensis, AplyL-1 exhibited the ability to agglutinate only the species L. amazonensis (at a concentration 77.5 ?g/mL). The results show that this new binding galactose derivatives lectin, could be important to development of new products with biotechnological and phylogenetic significance.