PubMed:18843533 JSONTXT

{"project":"sentences","denotations":[{"id":"TextSentencer_T1","span":{"begin":0,"end":149},"obj":"Sentence"},{"id":"TextSentencer_T2","span":{"begin":150,"end":285},"obj":"Sentence"},{"id":"TextSentencer_T3","span":{"begin":286,"end":505},"obj":"Sentence"},{"id":"TextSentencer_T4","span":{"begin":506,"end":784},"obj":"Sentence"},{"id":"TextSentencer_T5","span":{"begin":785,"end":997},"obj":"Sentence"},{"id":"TextSentencer_T6","span":{"begin":998,"end":1168},"obj":"Sentence"},{"id":"TextSentencer_T7","span":{"begin":1169,"end":1471},"obj":"Sentence"},{"id":"TextSentencer_T8","span":{"begin":1472,"end":1553},"obj":"Sentence"},{"id":"TextSentencer_T9","span":{"begin":1554,"end":1610},"obj":"Sentence"},{"id":"TextSentencer_T10","span":{"begin":1611,"end":1833},"obj":"Sentence"},{"id":"TextSentencer_T11","span":{"begin":1834,"end":1983},"obj":"Sentence"},{"id":"TextSentencer_T12","span":{"begin":1984,"end":2128},"obj":"Sentence"},{"id":"T1","span":{"begin":0,"end":149},"obj":"Sentence"},{"id":"T2","span":{"begin":150,"end":285},"obj":"Sentence"},{"id":"T3","span":{"begin":286,"end":505},"obj":"Sentence"},{"id":"T4","span":{"begin":506,"end":784},"obj":"Sentence"},{"id":"T5","span":{"begin":785,"end":997},"obj":"Sentence"},{"id":"T6","span":{"begin":998,"end":1168},"obj":"Sentence"},{"id":"T7","span":{"begin":1169,"end":1471},"obj":"Sentence"},{"id":"T8","span":{"begin":1472,"end":1553},"obj":"Sentence"},{"id":"T9","span":{"begin":1554,"end":1610},"obj":"Sentence"},{"id":"T10","span":{"begin":1611,"end":1833},"obj":"Sentence"},{"id":"T11","span":{"begin":1834,"end":1983},"obj":"Sentence"},{"id":"T12","span":{"begin":1984,"end":2128},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Adhesion forces in the self-recognition of oligosaccharide epitopes of the proteoglycan aggregation factor of the marine sponge Microciona prolifera.\nCell aggregation in the marine sponge Microciona prolifera is mediated by a multimillion molecular-mass aggregation factor, termed MAF. Earlier investigations revealed that the cell aggregation activity of MAF depends on two functional domains: (i) a Ca(2+)-independent cell-binding domain and (ii) a Ca(2+)-dependent proteoglycan self-interaction domain. Structural analysis of involved carbohydrate fragments of the proteoglycan in the self-association established a sulfated disaccharide beta-D: -GlcpNAc3S-(1--\u003e3)-alpha-L: -Fucp and a pyruvated trisaccharide beta-D: -Galp4,6(R)Pyr-(1--\u003e4)-beta-D: -GlcpNAc-(1--\u003e3)-alpha-L: -Fucp. Recent UV, SPR, and TEM studies, using BSA conjugates and gold nanoparticles of the synthetic sulfated disaccharide, clearly demonstrated self-recognition on the disaccharide level in the presence of Ca(2+)-ions. To determine binding forces of the carbohydrate-carbohydrate interactions for both synthetic MAF oligosaccharides, atomic force microscopy (AFM) studies were carried out. It turned out that, in the presence of Ca(2+)-ions, the force required to separate the tip and sample coated with a self-assembling monolayer of thiol-spacer-containing beta-D: -GlcpNAc-(1--\u003e3)-alpha-L: -Fucp-(1--\u003eO)(CH(2))(3)S(CH(2))(6)S- was found to be quantized in integer multiples of 30 +/- 6 pN. No binding was observed between the two monolayers in the absence of Ca(2+)-ions. Cd(2+)-ions could partially induce the self-interaction. In contrast, similar AFM experiments with thiol-spacer-containing beta-D: -Galp4,6(R)Pyr-(1--\u003e4)-beta-D: -GlcpNAc-(1--\u003e3)-alpha-L: -Fucp-(1--\u003eO)(CH(2))(3)S(CH(2))(6)S- did not show a binding in the presence of Ca(2+)-ions. Also TEM experiments of gold nanoparticles coated with the pyruvated trisaccharide could not make visible aggregation in the presence of Ca(2+)-ions. It is suggested that the self-interaction between the sulfated disaccharide fragments is stronger than that between the pyruvated trisaccharide."}

{"project":"NCBITAXON","denotations":[{"id":"T1","span":{"begin":128,"end":148},"obj":"OrganismTaxon"},{"id":"T2","span":{"begin":188,"end":208},"obj":"OrganismTaxon"}],"attributes":[{"id":"A1","pred":"db_id","subj":"T1","obj":"1190602"},{"id":"A2","pred":"db_id","subj":"T2","obj":"1190602"}],"text":"Adhesion forces in the self-recognition of oligosaccharide epitopes of the proteoglycan aggregation factor of the marine sponge Microciona prolifera.\nCell aggregation in the marine sponge Microciona prolifera is mediated by a multimillion molecular-mass aggregation factor, termed MAF. Earlier investigations revealed that the cell aggregation activity of MAF depends on two functional domains: (i) a Ca(2+)-independent cell-binding domain and (ii) a Ca(2+)-dependent proteoglycan self-interaction domain. Structural analysis of involved carbohydrate fragments of the proteoglycan in the self-association established a sulfated disaccharide beta-D: -GlcpNAc3S-(1--\u003e3)-alpha-L: -Fucp and a pyruvated trisaccharide beta-D: -Galp4,6(R)Pyr-(1--\u003e4)-beta-D: -GlcpNAc-(1--\u003e3)-alpha-L: -Fucp. Recent UV, SPR, and TEM studies, using BSA conjugates and gold nanoparticles of the synthetic sulfated disaccharide, clearly demonstrated self-recognition on the disaccharide level in the presence of Ca(2+)-ions. To determine binding forces of the carbohydrate-carbohydrate interactions for both synthetic MAF oligosaccharides, atomic force microscopy (AFM) studies were carried out. It turned out that, in the presence of Ca(2+)-ions, the force required to separate the tip and sample coated with a self-assembling monolayer of thiol-spacer-containing beta-D: -GlcpNAc-(1--\u003e3)-alpha-L: -Fucp-(1--\u003eO)(CH(2))(3)S(CH(2))(6)S- was found to be quantized in integer multiples of 30 +/- 6 pN. No binding was observed between the two monolayers in the absence of Ca(2+)-ions. Cd(2+)-ions could partially induce the self-interaction. In contrast, similar AFM experiments with thiol-spacer-containing beta-D: -Galp4,6(R)Pyr-(1--\u003e4)-beta-D: -GlcpNAc-(1--\u003e3)-alpha-L: -Fucp-(1--\u003eO)(CH(2))(3)S(CH(2))(6)S- did not show a binding in the presence of Ca(2+)-ions. Also TEM experiments of gold nanoparticles coated with the pyruvated trisaccharide could not make visible aggregation in the presence of Ca(2+)-ions. It is suggested that the self-interaction between the sulfated disaccharide fragments is stronger than that between the pyruvated trisaccharide."}