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Rômulo Farias Carneiro Renato Cézar Farias Torres Renata Pinheiro Chaves Mayron Alves de Vasconcelos Bruno Lopes de Sousa André Castelo Rodrigues Goveia Francisco Vassiliepe Arruda Maria Nágila Carneiro Matos Helena Matthews-Cascon Valder Nogueira Freire Edson Holanda Teixeira Celso Shiniti Nagano Alexandre Holanda Sampaio 《Marine biotechnology (New York, N.Y.)》2017,19(1):49-64
A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-activated Sepharose? media. Hemagglutination caused by ADEL was inhibited by several galactosides, mainly galacturonic acid (Ka = 6.05 × 106 M?1). The primary structure of ADEL consists of 217 residues, including 11 half-cystines involved in five intrachain and one interchain disulfide bond, resulting in a molecular mass of 57,228 ± 2 Da, as determined by matrix-assisted laser desorption/ionization time of flight mass spectrometry. ADEL showed high similarity with lectins isolated from Aplysia eggs, but not with other known lectins, indicating that these lectins could be grouped into a new family of animal lectins. Three glycosylation sites were found in its polypeptide backbone. Data from peptide-N-glycosidase F digestion and MS suggest that all oligosaccharides attached to ADEL are high in mannose. The secondary structure of ADEL is predominantly β-sheet, and its tertiary structure is sensitive to the presence of ligands, as observed by CD. A 3D structure model of ADEL was created and shows two domains connected by a short loop. Domain A is composed of a flat three-stranded and a curved five-stranded β-sheet, while domain B presents a flat three-stranded and a curved four-stranded β-sheet. Molecular docking revealed favorable binding energies for interactions between lectin and galacturonic acid, lactose, galactosamine, and galactose. Moreover, ADEL was able to agglutinate and inhibit biofilm formation of Staphylococcus aureus, suggesting that this lectin may be a potential alternative to conventional use of antimicrobial agents in the treatment of infections caused by Staphylococcal biofilms. 相似文献
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Nicolau Priante‐Filho George L. Vourlitis Mauro Massao Shiota Hayashi Jos De Souza Nogueira Jos Holanda Campelo Paulo Csar Nunes Luciana Sanches E Souza Eduardo Guimares Couto Wander Hoeger Fernando Raiter Jansen Luiz Trienweiler Eduardo Jacusiel Miranda Pedro Correto Priante Clvis Lasta Fritzen Moacir Lacerda Luiz Carlos Pereira Marcelo Sacardi Biudes George Sanches Suli Shozo Shiraiwa Srgio Roberto Do Paulo Marcos Silveira 《Global Change Biology》2004,10(5):863-876
This research utilized tower‐based eddy covariance to quantify the trends in net ecosystem mass (CO2 and H2O vapor) and energy exchange of important land‐cover types of NW Mato Grosso during the March–December 2002 seasonal transition. Measurements were made in a mature transitional (ecotonal) tropical forest near Sinop, Mato Grosso, and a cattle pasture near Cotriguaçú, Mato Grosso, located 500 km WNW of Sinop. Pasture net ecosystem CO2 exchange (NEE) was considerably more variable than the forest NEE over the seasonal transition, and the pasture had significantly higher rates of maximum gross primary production in every season except the dry–wet season transition (September–October). The pasture also had significantly higher rates of whole‐ecosystem dark respiration than the forest during the wetter times of the year. Average (±95% CI) rates of total daily NEE during the March–December 2002 measurement period were 26±15 mmol m?2 day?1 for the forest (positive values indicate net CO2 loss by the ecosystem) and ?38±26 mmol m?2 day?1 for the pasture. While both ecosystems partitioned more net radiation (Rn) into latent heat flux (Le), the forest had significantly higher rates of Le and lower rates of sensible heat flux (H) than the pasture; a trend that became more extreme during the onset of the dry season. Large differences in pasture and forest mass and energy exchange occurred even though seasonal variations in micrometeorology (air temperature, humidity, and radiation) were relatively similar for both ecosystems. While the short measurement period and lack of spatial replication limit the ability to generalize these results to pasture and forest regions of the Amazon Basin, these results suggest important differences in the magnitude and seasonal variation of NEE and energy partitioning for pasture and transitional tropical forest. 相似文献
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Porto Bárbara Alves da Silva Thamar Holanda Machado Mariana Resende de Oliveira Fábio Soares Rosa Carlos Augusto Rosa Luiz Henrique 《Extremophiles : life under extreme conditions》2020,24(5):797-807
Extremophiles - We recovered 85 fungal isolates from the acid sulphate soils in chronosequence under para-periglacial conditions in King George Island, Antarctica. Thirty-two taxa belonging to the... 相似文献
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Mitochondrial genome diversity of Native Americans supports a single early entry of founder populations into America 总被引:9,自引:0,他引:9 下载免费PDF全文
Silva WA Bonatto SL Holanda AJ Ribeiro-Dos-Santos AK Paixão BM Goldman GH Abe-Sandes K Rodriguez-Delfin L Barbosa M Paçó-Larson ML Petzl-Erler ML Valente V Santos SE Zago MA 《American journal of human genetics》2002,71(1):187-192
There is general agreement that the Native American founder populations migrated from Asia into America through Beringia sometime during the Pleistocene, but the hypotheses concerning the ages and the number of these migrations and the size of the ancestral populations are surrounded by controversy. DNA sequence variations of several regions of the genome of Native Americans, especially in the mitochondrial DNA (mtDNA) control region, have been studied as a tool to help answer these questions. However, the small number of nucleotides studied and the nonclocklike rate of mtDNA control-region evolution impose several limitations to these results. Here we provide the sequence analysis of a continuous region of 8.8 kb of the mtDNA outside the D-loop for 40 individuals, 30 of whom are Native Americans whose mtDNA belongs to the four founder haplogroups. Haplogroups A, B, and C form monophyletic clades, but the five haplogroup D sequences have unstable positions and usually do not group together. The high degree of similarity in the nucleotide diversity and time of differentiation (i.e., approximately 21,000 years before present) of these four haplogroups support a common origin for these sequences and suggest that the populations who harbor them may also have a common history. Additional evidence supports the idea that this age of differentiation coincides with the process of colonization of the New World and supports the hypothesis of a single and early entry of the ancestral Asian population into the Americas. 相似文献
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The record of the genus Tapirus in South America is associated with the faunistic events of the Great American Biotic Interchange (GABI). The taxon is considered an immigrant of Holarctic origin. Although remains are scarce and incomplete during the Pleistocene, an analysis of these materials allowed us to consider valid seven fossil species : Tapirus tarijensis, T. cristatellus, T. greslebini, T. rioplatensis, T. oliverasi, T. mesopotamicus, and T. rondoniensis. A phylogenetic analysis was carried out in order to elucidate the relationships of the American fossil and extant species. Our result is consistent with a paraphyletic hypothesis for South American tapirs and suggests that a second dispersal event would have occurred from South America to North America, of a form closely related to T. cristatellus, resulting in the derived forms of North America. 相似文献
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Germán Mariano Gasparini Elizete Celestino Holanda Hermínio Ismael de Araújo-Júnior Leonardo dos Santos Avilla 《Historical Biology》2016,28(6):803-811
During fieldworks carried out from 2009 to 2013 in Aurora do Tocantins (northern Brazil), three isolated deciduous teeth of Tapirus were recovered. Those fossils come from a sedimentary deposit of presumed Late Pleistocene–early Holocene age in a karstic cave. This contribution aims to present a new locality of fossil Tapirus from northern Brazil, describe for the first time deciduous fossil teeth for South American Tapirus and evaluate the taphonomic aspects of those fossils. The specimens probably belong to the same individual due to there are no repeated teeth and they have the same wear pattern. Furthermore, the crowns of those teeth show no evidence of abrasion produced by transport. However, some abrasion is observed on the borders of the pulp chamber of teeth. These polishing are probably resulting of a very short transport (parautochthonous). These specimens are the only record of Tapiridae in Gruta do Urso cave; due to correspond to isolated and deciduous teeth, its identification to species level was not possible. There is not yet clear evidence that may indicate the kind of death of the individual studied here. 相似文献
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Souza Teixeira C da Silva HC de Moura TR Pereira-Júnior FN do Nascimento KS Nagano CS Sampaio AH Delatorre P Rocha BA Cavada BS 《Journal of biochemistry》2012,152(1):87-98
Lectins have been used as models for studies of the molecular basis of protein-carbohydrate interaction and specificity by deciphering codes present in the glycan structures. The purpose of the present study was to purify and solve the complete primary and crystal structure of the lectin of Camptosema pedicellatum (CPL) complexed with 5-bromo-4-chloro-3-indolyl-α-d-mannose (X-Man) using tandem mass spectrometry. CPL was purified by single-step affinity chromatography. Mass spectrometry findings revealed that purified CPL features a combination of chains weighing 25,298 ± 2 (α-chain), 12,835 ± 2 (β-chain) and 12,481 ± 2 Da (γ-chain). The solved crystal structure of CPL features a conservative mutation in the hydrophobic subsite, a constituent of the carbohydrate recognition domain (CRD), indicating the relevance of hydrophobic interactions in the establishment of interactions with carbohydrates. The substitution and the analysis of the interactions with X-Man also revealed that the hydrophobic effect caused by a minor change in the hydrophobic subsite interferes in the formation of H-bonds due to the reorientation of the indolyl group in the CRD. 相似文献
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Plinio Delatorre José Caetano Silva-Filho Bruno Anderson Matias Rocha Tatiane Santi-Gadelha Raphael Batista da Nóbrega Carlos Alberto Almeida Gadelha Kyria Santiago do Nascimento Celso Shiniti Nagano Alexandre Holanda Sampaio Benildo Sousa Cavada 《Biochimie》2013
Indole-3-acetic acid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 Å resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for legume lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination. 相似文献
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de Oliveira Silva F das Neves Santos P de Melo CM Teixeira EH de Sousa Cavada B Arruda FV Cajazeiras JB Almeida AC Pereira VA Porto AL 《Cell and tissue research》2011,346(2):237-244
Lectins constitute a class of glycoproteins, which are capable of selectively and reversibly binding to carbohydrates, distinguishing
small structural differences in complex oligosaccharides. Studies have shown that the binding of lectins to cell-surface carbohydrates
can lead to various effects such as cellular proliferation, histamine release and cytokine production. Canavalia brasiliensis lectin (ConBr) is a (D-mannose) D-glucose lectin. In this study, murine splenocytes were cultured to determine the effect
of ConBr on cell proliferation, nitric oxide (NO) release and cytokine secretion. In addition, cellular viability assays were
performed to evaluate any mitogenic activity induced by this lectin. ConBr significantly increased cell proliferation with
minimal cell damage. This lectin was able to induce an increased production of cytokines such as IL-2, IL-6 and IFN-γ and
a decreased production of IL- 10. The release of NO was also observed. The results of this study indicate that ConBr could
potentially be used as an immunomodulator. 相似文献