Beatriz Mothes

ACL-I, a lectin from the marine sponge Axinella corrugata: isolation, characterization and chemotactic activity.

The lectin from the marine sponge Axinella corrugata (ACL-I) was purified by affinity chromatography on rabbit erythrocytic stroma incorporated into a polyacrylamide gel followed by gel filtration on Ultrogel AcA 44 column. Purified ACL-I is a hexameric glycoprotein with a Mr of 82.3 kDa estimated by SDS-PAGE and 78.5 kDa by FPLC on Superose 12 HR column. The pI of lectin is 6.3 and ACL-I is constituted of 13.9 kDa similar subunits some of them linked by disulphide bridges. This lectin agglutinates native rabbit, goat and dog erythrocytes and in less extent human erythrocytes. The hemagglutinating activity is independent of Ca(2+), Mg(2+) and Mn(2+), but it is strongly inhibited by carbohydrates containing N-acetyl groups. ACL-I is stable up to 70 degrees C for 30 min, with optimum pH between 7 and 8, and it is also resistant to enzymatic proteolysis in vitro. In the presence of reducing or denaturant agents, the lectin activity decreases. ACL-I displays chemotactic effect on rat neutrophil in vitro which is inhibited by N-acetyl-d-glucosamine.

Current Status on Natural Products with Antitumor Activity from Brazilian Marine Sponges

Over the last few years, samples from the marine environment have been screened for a variety of compounds with different biological activities. Among all marine organisms, sponges represent one of the most promising sources of leads in the research of new cancer drugs. However, there are few reports on screening Brazilian marine sponges for biological activities. In the following review, the current status of natural product research relating to Brazilian marine sponges is summarized, particularly for compounds demonstrating potential antitumor activity.

Biological activities of ACL-I and physicochemical properties of ACL-II, lectins isolated from the marine sponge Axinella corrugata

Lectin II from the marine sponge Axinella corrugata (ACL-II) was purified by affinity chromatography on rabbit erythrocytic stroma incorporated into a polyacrylamide gel, followed by gel filtration on Ultrogel AcA 44 column. Purified ACL-II is a lectin with an Mr of 80 kDa and 78 kDa, estimated by SDS-PAGE and by FPLC on Superose 12 HR column, respectively. ACL-II mainly agglutinates native rabbit erythrocytes and this hemagglutinating activity is independent of Ca(2+), Mg(2+) and Mn(2+), but is inhibited by d-galactose, chitin and N-acetyl derivatives, with the exception of GalNAc. ACL-II is stable for up to 65 °C for 30 min, with a better stability at a pH range of 2 to 6. In contrast, ACL-I displays a strong mitogenic and cytotoxic effect.

. Esponjas Antárticas (Porifera, Demospongiae) das Ilhas Shetland do Sul e áreas próximas. Parte I. Spirophorida, Astrophorida, Hadromerida, Halichondrida e Haplosclerida

The aim of this work is to redescribe 11 species of sponges collected through the Brazilian Antarctic Program (PROANTAR), at the South Shetland Islands and vicinity. New information is provided on the Antarctic sponge fauna, in regard to species richness and the geographical and bathymetric distributions of identified species. The following species were identified and are here illustrated and fully described: Cinachyra antarctica (Carter, 1872), Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886), Tethyopsis longispinum (Lendenfeld, 1907), Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886), Suberites montiniger Carter, 1880, Halichondria (Eumastia) attenuata (Topsent, 1915), Haliclona (Soestella) chilensis (Thiele, 1905), Hemigellius bidens (Topsent, 1901) and Calyx arcuarius (Topsent, 1913). Two new records are given for the Antarctic continent: Halichondria (Eumastia) attenuata (Topsent, 1915) and Haliclona (Soestella) chilensis (Thiele, 1905). Tethyopsis longispinum (Lendenfeld, 1907), Suberites montiniger Carter, 1880 and Hemigellius bidens (Topsent, 1901) represent the first records for this sector of the continent. Bathymetric data are extended for T . longispinum and H . attenuata .

Novos registros e ampliação de limites meridionais de distribuição de poríferos (Porifera, Demospongiae) no Atlântico sudoeste

The southern boundaries of seven species of Brazilian coast sponges were enlarged. Two of them represent new records: Chalinula zeae de Weerdt, 2000 e Terpios manglaris Rutzler & Smith, 1993 and five were registered for the first time from the state of Santa Catarina: Callyspongia (Toxochalina) pseudotoxa Muricy & Ribeiro, 1999; Mycale (Carmia) magnirhaphidifera van Soest, 1984; Hymeniacidon heliophila Parker, 1910; Monanchora arbuscula (Duchassaing & Michelotti, 1864) and Scopalina ruetzleri (Wiedenmayer, 1977). The taxonomic description of species is also provided and the three latter were described for the first time from the Brazilian coast, since other authors only cited it.

Esponjas (Demospongiae, Halichondrida) da costa do Maranhão, Brasil

Three species of Halichondrida, Dragmacidon reticulatus (Ridley & Dendy, 1886) (Axinellidae), Myrmekioderma rea (Laubenfels, 1934) (Desmoxyidae) and Topsentia ophiraphidites (Laubenfels, 1934) (Halichondriidae), collected from 30 to 184 m depths, were recorded for the first time from State of Maranhao, north-northeast coast of Brazilian shelf.

Antibiofilm activity of Cobetia marina filtrate upon Staphylococcus epidermidis catheter-related isolates

We report the antibiofilm activity by the sponge-associated bacterium Cobetia marina upon Staphylococcus epidermidis clinical isolates obtained from central venous catheters. Antibiofilm activity/antimicrobial susceptibility correlation might predict the action of the metabolite(s) upon Staphylococcus epidermidis in the clinic, making it a possible adjuvant in therapies against biofilm-associated infections.

Antarctic sponges (Porifera, Demospongiae) of the South Shetland Islands and vicinity: part II. Poecilosclerida

In the present study 16 species are registered for the South Shetland Islands and vicinity: Acanthorhabdus fragilis Burton, 1929, Iophon unicornis Topsent, 1907, Clathria (Axosuberites) flabellata (Topsent, 1916), Clathria (Axosuberites) nidificata (Kirkpatrick, 1907), Kirkpatrickia variolosa (Kirkpatrick, 1907), Myxodoryx hanitschi (Kirkpatrick, 1907), Iotroata somovi (Koltun, 1964), Tedania (Tedaniopsis) charcoti (Topsent, 1907), Tedania (Tedaniopsis) vanhoffeni (Hentschel, 1914), Tedania (Tedaniopsis) oxeata (Topsent, 1916), Isodictya kerguelenensis (Ridley & Dendy, 1886), Isodictya lankesteri (Kirkpatrick, 1907), Isodictya toxophila Burton, 1932, Isodictya bentarti Rios, Cristobo & Urgorri, 2004, Latrunculia (Latrunculia) brevis Ridley & Dendy, 1886 and Latrunculia (Latrunculia) biformis (Kirkpatrick, 1908). Amongst the identified species, five are new occurrences for the studied region, three have their bathymetric limit extended and the others are confirmed for the studied area.

Recruitment and colonization of colonial ascidians (Tunicata: Ascidiacea) on intertidal rocks in Northeastern Brazil

Recruitment and colonization of colonial ascidians, starting on natural scraped substratum, was observed throughout one year, in quadrats marked on sea- and continental-rock faces in the sublittoral fringe of an exposed beach in the Northeast of Brazil. The species of the Didemnidae, Didemnum duplicatum Monniot, 1983, D. psammathodes Sluiter, 1895, and Polysyncraton amethysteum Van Name, 1902, and an unidentified species of Polycitoridae, Eudistoma sp. 1, were recruited. Presenting continuous recruitment of all species, the density of living and dead recruits and colonies was similar on both faces of the rocks. The highest rainfall during winter, affected significantly the recruits density of D. duplicatum and D. psammathodes. Different permanence periods were observed for colonies of each species. The longest permanence periods were assigned to the colonies of P. amethysteum and D. psammathodes, extending up to four and five months, respectively.

Immunohistochemical localization of an N-acetyl amino-carbohydrate specific lectin (ACL-I) of the marine sponge Axinella corrugata.

The N-acetyl amino-carbohydrate specific lectin (ACL-I) was previously identified and purified by us from the marine sponge Axinella corrugata (phylum Porifera, class Demospongiae). The distribution of the specific lectin within the tissue of the sponge was studied by bright-field optical microscopy immunohistochemistry in order to better understand its physiological role in the sponge. Polyclonal antibodies were raised against purified ACL-I in mice and tested by Western blot technique. The immunohistochemical analysis of ACL-I in cross sections of A. corrugata showed that this lectin is found inside the denominated spherulous cells, which contain vesicles that store the lectin. Some evidence is shown that ACL-I might also be present in the extracellular matrix. It was not possible to demonstrate by the immunohistochemical technique if ACL-I is colocalized in both the plasma membrane and in the cytoplasm of the spherulous cells.