RESUMO
AIMS: Bacillus anthracis strains of various origins were analysed with the view to describe intrinsic and persistent structural components of the Bacillus collagen-like protein of anthracis glycoprotein associated anthrose containing tetrasaccharide in the exosporium. METHODS AND RESULTS: The tetrasaccharide consists of three rhamnose residues and an unique monosaccharide--anthrose. As anthrose was not found in spores of related strains of bacteria, we envisioned the detection of B. anthracis spores based on antibodies against anthrose-containing polysaccharides. Carbohydrate-protein conjugates containing the synthetic tetrasaccharide, an anthrose-rhamnose disaccharide or anthrose alone were employed to immunize mice. All three formulations were immunogenic and elicited IgG responses with different fine specificities. All sera and monoclonal antibodies derived from tetrasaccharide immunized mice cross-reacted not only with spore lysates of a panel of virulent B. anthracis strains, but also with some of the B. cereus strains tested. CONCLUSIONS: Our results demonstrate that antibodies to synthetic carbohydrates are useful tools for epitope analyses of complex carbohydrate antigens and for the detection of particular target structures in biological specimens. SIGNIFICANCE AND IMPACT OF THE STUDY: Although not strictly specific for B. anthracis spores, antibodies against the tetrasaccharide may have potential as immuno-capturing components for a highly sensitive spore detection system.
Assuntos
Amino Açúcares/química , Bacillus anthracis/fisiologia , Bacillus cereus/fisiologia , Western Blotting/métodos , Desoxiglucose/análogos & derivados , Amino Açúcares/imunologia , Amino Açúcares/metabolismo , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Configuração de Carboidratos , Reações Cruzadas , DNA Bacteriano/genética , Desoxiglucose/química , Desoxiglucose/imunologia , Desoxiglucose/metabolismo , Ensaio de Imunoadsorção Enzimática , Regulação Bacteriana da Expressão Gênica/fisiologia , Humanos , Soros Imunes/imunologia , Imunoglobulina G/sangue , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Processamento de Proteína Pós-Traducional , Esporos Bacterianos/fisiologiaRESUMO
The reaction of the cyclic tetrathiadiynes 4(m.n) (where m and n indicate the number of methylene groups between the dithiaacetylene units) with sodium trichloroacetate and subsequent hydrolysis of the gem-dichlorocyclopropenes afforded the mono- and biscyclopropenone derivatives 5(m.n) and 6(m.n) in moderate yields. Investigation of the X-ray crystal structures revealed small torsion angles between the CH(2)-S bond and the C-C double bond, indicating conjugation between the sulfur 3p lone pair and the cyclopropenone ring. The maintenance of the conjugation determines the secondary structure of both (5, 6) ring systems.
