Structure of a lectin from Canavalia gladiata seeds: new structural insights for old molecules

<p>Abstract</p> <p>Background</p> <p>Lectins are mainly described as simple carbohydrate-binding proteins. Previous studies have tried to identify other binding sites, which possible recognize plant hormones, secondary metabolites, and isolated amino acid residues. We report the crystal structure of a lectin isolated from <it>Canavalia gladiata </it>seeds (CGL), describing a new binding pocket, which may be related to pathogen resistance activity in ConA-like lectins; a site where a non-protein amino-acid, α-aminobutyric acid (Abu), is bound.</p> <p>Results</p> <p>The overall structure of native CGL and complexed with α-methyl-mannoside and Abu have been refined at 2.3 Å and 2.31 Å resolution, respectively. Analysis of the electron density maps of the CGL structure shows clearly the presence of Abu, which was confirmed by mass spectrometry.</p> <p>Conclusion</p> <p>The presence of Abu in a plant lectin structure strongly indicates the ability of lectins on carrying secondary metabolites. Comparison of the amino acids composing the site with other legume lectins revealed that this site is conserved, providing an evidence of the biological relevance of this site. This new action of lectins strengthens their role in defense mechanisms in plants.</p

Doença de Erdheim Chester com envolvimento isolado do SNC: Erdheim Chester disease with isolated CNS involvement

Introdução: A Doença de Erdheim-Chester é&nbsp; uma forma de&nbsp; histiocitose&nbsp; de&nbsp; células&nbsp; não-Langerhans&nbsp; que&nbsp; ocorre&nbsp; mais&nbsp; frequentemente&nbsp; após&nbsp; os&nbsp; 40&nbsp; anos&nbsp; de&nbsp; idade,&nbsp; com leve&nbsp; predomínio&nbsp; no&nbsp; sexo&nbsp; masculino. Apresentação do caso: Paciente, sexo masculino, branco, X anos de idade, admitido no Hospital das Clínicas de Goiânia, com sintomas de cefaléia crônica, de caráter progressivo de inicio há 3 meses, associados a sintomas neurológicos de ataxia e diplopia. Referiu febre baixa diária, não aferida, com perda de 10kg no período descrito, não associado a dieta ou mudança de hábitos de vida. Nega comorbidades ou uso de medicamentos.&nbsp; Ao exame físico, apresenta quadro de Nistagmo e Romberg positivo e alteração da úvula para direita. Paciente não apresentava outros sinais dignos de nota. Discussão: Foram selecionados para a revisão, os artigos de relato de caso ou séries de caso relacionados a manifestações clínicas da doença de Erdheim-Chester. Os principais tipos manifestações clínicas relatadas na literatura são: neurológicas, cardiovasculares, oftálmicas, endócrinas, urinárias, hematológicas, ósseas, cutâneas, respiratórias, gastrointestinais, envolvimento de múltiplos sistemas e outras. Entre esses tipos de manifestações, as mais frequentes foram neurológicas, cardiovasculares e oftálmicas, correspondendo a 48% das manifestações relatadas. Conclusão: É fundamental ter uma equipe multidisciplinar acompanhando o paciente,&nbsp; para que sejam evitadas complicações e se possa proporcionar qualidade de vida ao paciente. &nbsp

Melanoma maligno da próstata primária : Malignant melanoma of the primary prostate

Introdução: Descreve-se um caso de melanoma maligno da próstata primário. Será possível compreender que a próstata é um local raro de se encontrar um melanoma maligno primário e que devido a sua infrequência, possui um prognóstico ruim e um difícil diagnóstico. Apresentação do caso: Paciente do sexo masculino, 47 anos, solteiro, negro, motorista de caminhão, compareceu a UBS com queixa de jato urinário fraco, nocturia e hematoespermia, 3 episódios, início há um ano. Discussão:&nbsp; Grande parte dos casos relatados, são de origem do epitélio de transição da uretra prostática ou de uma lesão metastática.&nbsp; Essa patologia possui um comportamento altamente agressivo e deve receber grande atenção. Devido a sua infrequência, é de difícil diagnóstico e tratamento. O tratamento indicado é a excisão, se o paciente não tiver doença sistêmica. Conclusão: o conhecimento dessa patologia e sua suspeição devem ser melhor propagados no meio científico, para que haja o diagnóstico e posterior tratamento mais precocemente possível, objetivando melhores prognósticos

SURVEY OF SANDFLY FAUNA (DIPTERA: PSYCHODIDAE) IN UBERLÂNDIA, MINAS GERAIS STATE, BRAZIL, 2003-2004

We analyzed the sandflies around houses and domestic animal shelters located in residences close to forests in localities on the banks of the Araguari River, Uberl&#226;ndia, MG, from February 2003 to November 2004. The phlebotomines were captured in the peridomiciliary area, where Shannon traps were utilized in the peridomicile and CDC traps in animal shelters. 2,783 specimens of sandflies were captured, 2,140 females (76.9%) and 643 males (23.1%), distributed between 17 species. The most abundant species was Nyssomyia neivai (88.1%), followed by Nyssomyia whitmani (3.1%). The presence of Lutzomyia longipalpis was also confirmed, it is the main vector of Leishmania (L.) infantum chagasi which causes visceral leishmaniasis. The presence of species involved in the transmission of leishmaniases in the municipality of Uberl&#226;ndia is cause for concern. The presence of L. longipalpis indicates that its urbanization may not have been aleatory and instead occurred through the destruction of wild ecotopes. More studies of their occupation in anthropic environments need to be made

Transcription profiling of signal transduction-related genes in sugarcane tissues

A collection of 237,954 sugarcane ESTs was examined in search of signal transduction genes. Over 3,500 components involved in several aspects of signal transduction, transcription, development, cell cycle, stress responses and pathogen interaction were compiled into the Sugarcane Signal Transduction (SUCAST) Catalogue. Sequence comparisons and protein domain analysis revealed 477 receptors, 510 protein kinases, 107 protein phosphatases, 75 small GTPases, 17 G-proteins, 114 calcium and inositol metabolism proteins, and over 600 transcription factors. The elements were distributed into 29 main categories subdivided into 409 sub-categories. Genes with no matches in the public databases and of unknown function were also catalogued. A cDNA microarray was constructed to profile individual variation of plants cultivated in the field and transcript abundance in six plant organs (flowers, roots, leaves, lateral buds, and 1(st) and 4(th) internodes). From 1280 distinct elements analyzed, 217 (17%) presented differential expression in two biological samples of at least one of the tissues tested. A total of 153 genes (12%) presented highly similar expression levels in all tissues. A virtual profile matrix was constructed and the expression profiles were validated by real-time PCR. The expression data presented can aid in assigning function for the sugarcane genes and be useful for promoter characterization of this and other economically important grasses.121273

Native crystal structure of a nitric oxide-releasing lectin from the seeds of Canavalia maritima

Here, we report the crystallographic study of a lectin from Canavalia maritima seeds (ConM) and its relaxant activity on vascular smooth muscle, to provide new insights into the understanding of structure/function relationships of this class of proteins. ConM was crystallized and its structure determined by standard molecular replacement techniques. The amino acid residues, previously suggested incorrectly by manual sequencing, have now been determined as I17, I53, S129, S134, G144, S164, P165, S187, V190, S169, T196, and S202. Analysis of the structure indicated a dimer in the asymmetric unit, two metal binding sites per monomer, and loops involved in the molecular oligomerization. These confer 98% similarity between ConM and other previously described lectins, derived from Canavalia ensiformis and Canavalia brasiliensis. Our functional data indicate that ConM exerts a concentration-dependent relaxant action on isolated aortic rings that probably occurs via an interaction with a specific lectin-binding site on the endothelium, resulting in a release of nitric oxide. (C) 2005 Elsevier B.V. All rights reserved