PubMed:11996839 JSONTXT

{"project":"sentences","denotations":[{"id":"TextSentencer_T1","span":{"begin":0,"end":133},"obj":"Sentence"},{"id":"TextSentencer_T2","span":{"begin":134,"end":324},"obj":"Sentence"},{"id":"TextSentencer_T3","span":{"begin":325,"end":433},"obj":"Sentence"},{"id":"TextSentencer_T4","span":{"begin":434,"end":620},"obj":"Sentence"},{"id":"TextSentencer_T5","span":{"begin":621,"end":656},"obj":"Sentence"},{"id":"TextSentencer_T6","span":{"begin":657,"end":736},"obj":"Sentence"},{"id":"TextSentencer_T7","span":{"begin":737,"end":816},"obj":"Sentence"},{"id":"TextSentencer_T8","span":{"begin":817,"end":988},"obj":"Sentence"},{"id":"TextSentencer_T9","span":{"begin":989,"end":1076},"obj":"Sentence"},{"id":"TextSentencer_T10","span":{"begin":1077,"end":1193},"obj":"Sentence"},{"id":"TextSentencer_T11","span":{"begin":1194,"end":1319},"obj":"Sentence"},{"id":"TextSentencer_T12","span":{"begin":1320,"end":1442},"obj":"Sentence"},{"id":"TextSentencer_T13","span":{"begin":1443,"end":1578},"obj":"Sentence"},{"id":"T1","span":{"begin":0,"end":133},"obj":"Sentence"},{"id":"T2","span":{"begin":134,"end":324},"obj":"Sentence"},{"id":"T3","span":{"begin":325,"end":433},"obj":"Sentence"},{"id":"T4","span":{"begin":434,"end":620},"obj":"Sentence"},{"id":"T5","span":{"begin":621,"end":656},"obj":"Sentence"},{"id":"T6","span":{"begin":657,"end":736},"obj":"Sentence"},{"id":"T7","span":{"begin":737,"end":816},"obj":"Sentence"},{"id":"T8","span":{"begin":817,"end":988},"obj":"Sentence"},{"id":"T9","span":{"begin":989,"end":1076},"obj":"Sentence"},{"id":"T10","span":{"begin":1077,"end":1193},"obj":"Sentence"},{"id":"T11","span":{"begin":1194,"end":1319},"obj":"Sentence"},{"id":"T12","span":{"begin":1320,"end":1442},"obj":"Sentence"},{"id":"T13","span":{"begin":1443,"end":1578},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"Glycosmos6-MAT","denotations":[{"id":"T1","span":{"begin":1402,"end":1408},"obj":"http://purl.obolibrary.org/obo/MAT_0000091"},{"id":"T2","span":{"begin":1571,"end":1577},"obj":"http://purl.obolibrary.org/obo/MAT_0000091"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"Glycan-GlyCosmos","denotations":[{"id":"T1","span":{"begin":35,"end":45},"obj":"Glycan"},{"id":"T2","span":{"begin":218,"end":228},"obj":"Glycan"},{"id":"T3","span":{"begin":475,"end":485},"obj":"Glycan"},{"id":"T4","span":{"begin":1345,"end":1355},"obj":"Glycan"}],"attributes":[{"id":"A1","pred":"glycosmos_id","subj":"T1","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A5","pred":"image","subj":"T1","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"},{"id":"A2","pred":"glycosmos_id","subj":"T2","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A6","pred":"image","subj":"T2","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"},{"id":"A3","pred":"glycosmos_id","subj":"T3","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A7","pred":"image","subj":"T3","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"},{"id":"A4","pred":"glycosmos_id","subj":"T4","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A8","pred":"image","subj":"T4","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"GlyCosmos15-UBERON","denotations":[{"id":"T1","span":{"begin":329,"end":334},"obj":"Body_part"},{"id":"T2","span":{"begin":1043,"end":1048},"obj":"Body_part"},{"id":"T3","span":{"begin":1409,"end":1414},"obj":"Body_part"}],"attributes":[{"id":"A1","pred":"uberon_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/UBERON_0000464"},{"id":"A2","pred":"uberon_id","subj":"T2","obj":"http://purl.obolibrary.org/obo/UBERON_0000464"},{"id":"A3","pred":"uberon_id","subj":"T3","obj":"http://purl.obolibrary.org/obo/UBERON_0002488"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"GlyCosmos15-MAT","denotations":[{"id":"T1","span":{"begin":1402,"end":1408},"obj":"Body_part"},{"id":"T2","span":{"begin":1571,"end":1577},"obj":"Body_part"}],"attributes":[{"id":"A1","pred":"mat_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/MAT_0000091"},{"id":"A2","pred":"mat_id","subj":"T2","obj":"http://purl.obolibrary.org/obo/MAT_0000091"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"sentences","denotations":[{"id":"TextSentencer_T1","span":{"begin":0,"end":133},"obj":"Sentence"},{"id":"TextSentencer_T2","span":{"begin":134,"end":324},"obj":"Sentence"},{"id":"TextSentencer_T3","span":{"begin":325,"end":433},"obj":"Sentence"},{"id":"TextSentencer_T4","span":{"begin":434,"end":620},"obj":"Sentence"},{"id":"TextSentencer_T5","span":{"begin":621,"end":656},"obj":"Sentence"},{"id":"TextSentencer_T6","span":{"begin":657,"end":736},"obj":"Sentence"},{"id":"TextSentencer_T7","span":{"begin":737,"end":816},"obj":"Sentence"},{"id":"TextSentencer_T8","span":{"begin":817,"end":988},"obj":"Sentence"},{"id":"TextSentencer_T9","span":{"begin":989,"end":1076},"obj":"Sentence"},{"id":"TextSentencer_T10","span":{"begin":1077,"end":1193},"obj":"Sentence"},{"id":"TextSentencer_T11","span":{"begin":1194,"end":1319},"obj":"Sentence"},{"id":"TextSentencer_T12","span":{"begin":1320,"end":1442},"obj":"Sentence"},{"id":"TextSentencer_T13","span":{"begin":1443,"end":1578},"obj":"Sentence"},{"id":"T1","span":{"begin":0,"end":133},"obj":"Sentence"},{"id":"T2","span":{"begin":134,"end":324},"obj":"Sentence"},{"id":"T3","span":{"begin":325,"end":433},"obj":"Sentence"},{"id":"T4","span":{"begin":434,"end":620},"obj":"Sentence"},{"id":"T5","span":{"begin":621,"end":656},"obj":"Sentence"},{"id":"T6","span":{"begin":657,"end":736},"obj":"Sentence"},{"id":"T7","span":{"begin":737,"end":816},"obj":"Sentence"},{"id":"T8","span":{"begin":817,"end":988},"obj":"Sentence"},{"id":"T9","span":{"begin":989,"end":1076},"obj":"Sentence"},{"id":"T10","span":{"begin":1077,"end":1193},"obj":"Sentence"},{"id":"T11","span":{"begin":1194,"end":1319},"obj":"Sentence"},{"id":"T12","span":{"begin":1320,"end":1442},"obj":"Sentence"},{"id":"T13","span":{"begin":1443,"end":1578},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"GlyCosmos15-Sentences","blocks":[{"id":"T1","span":{"begin":0,"end":133},"obj":"Sentence"},{"id":"T2","span":{"begin":134,"end":324},"obj":"Sentence"},{"id":"T3","span":{"begin":325,"end":433},"obj":"Sentence"},{"id":"T4","span":{"begin":434,"end":620},"obj":"Sentence"},{"id":"T5","span":{"begin":621,"end":656},"obj":"Sentence"},{"id":"T6","span":{"begin":657,"end":736},"obj":"Sentence"},{"id":"T7","span":{"begin":737,"end":816},"obj":"Sentence"},{"id":"T8","span":{"begin":817,"end":988},"obj":"Sentence"},{"id":"T9","span":{"begin":989,"end":1076},"obj":"Sentence"},{"id":"T10","span":{"begin":1077,"end":1193},"obj":"Sentence"},{"id":"T11","span":{"begin":1194,"end":1319},"obj":"Sentence"},{"id":"T12","span":{"begin":1320,"end":1442},"obj":"Sentence"},{"id":"T13","span":{"begin":1443,"end":1578},"obj":"Sentence"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"GlyCosmos15-Glycan","denotations":[{"id":"T1","span":{"begin":35,"end":45},"obj":"Glycan"},{"id":"T2","span":{"begin":218,"end":228},"obj":"Glycan"},{"id":"T3","span":{"begin":475,"end":485},"obj":"Glycan"},{"id":"T4","span":{"begin":1345,"end":1355},"obj":"Glycan"}],"attributes":[{"id":"A1","pred":"glycosmos_id","subj":"T1","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A5","pred":"image","subj":"T1","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"},{"id":"A2","pred":"glycosmos_id","subj":"T2","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A6","pred":"image","subj":"T2","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"},{"id":"A3","pred":"glycosmos_id","subj":"T3","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A7","pred":"image","subj":"T3","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"},{"id":"A4","pred":"glycosmos_id","subj":"T4","obj":"https://glycosmos.org/glycans/show/G55560AP"},{"id":"A8","pred":"image","subj":"T4","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G55560AP"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"Anatomy-UBERON","denotations":[{"id":"T1","span":{"begin":329,"end":334},"obj":"Body_part"},{"id":"T2","span":{"begin":1043,"end":1048},"obj":"Body_part"},{"id":"T3","span":{"begin":1409,"end":1414},"obj":"Body_part"}],"attributes":[{"id":"A1","pred":"uberon_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/UBERON_0000464"},{"id":"A2","pred":"uberon_id","subj":"T2","obj":"http://purl.obolibrary.org/obo/UBERON_0000464"},{"id":"A3","pred":"uberon_id","subj":"T3","obj":"http://purl.obolibrary.org/obo/UBERON_0002488"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}

{"project":"Anatomy-MAT","denotations":[{"id":"T1","span":{"begin":1402,"end":1408},"obj":"Body_part"},{"id":"T2","span":{"begin":1571,"end":1577},"obj":"Body_part"}],"attributes":[{"id":"A1","pred":"mat_id","subj":"T1","obj":"http://purl.obolibrary.org/obo/MAT_0000091"},{"id":"A2","pred":"mat_id","subj":"T2","obj":"http://purl.obolibrary.org/obo/MAT_0000091"}],"text":"The crystal structure of the alpha-cellobiose.2 NaI.2 H(2)O complex in the context of related structures and conformational analysis.\nThe crystal structure of beta-D-glucopyranosyl-(1--\u003e4)-alpha-D-glucopyranose (alpha-cellobiose) in a complex with water and NaI was determined with Mo K(alpha) radiation at 150 K to R=0.027. The space group is P2(1) and unit cell dimensions are a=9.0188, b=12.2536, c=10.9016 A, beta=97.162 degrees. There are no direct hydrogen bonds among cellobiose molecules, and the usual intramolecular hydrogen bond between O-3 and O-5' is replaced by a bridge involving Na+, O-3, O-5', and O-6'. Both Na+ have sixfold coordination. One I(-) accepts six donor hydroxyl groups and three C-H***I(-) hydrogen bonds. The other accepts three hydroxyls, one Na+, and five C-H***I(-) hydrogen bonds. Linkage torsion angles phi(O-5) and psi(C-5) are -73.6 and -105.3 degrees, respectively (phi(H)=47.1 degrees and psi(H)=14.6 degrees ), probably induced by the Na+ bridge. This conformation is in a separate cluster in phi,psi space from most similar linkages. Both C-6-O-H and C-6'-O-H are gg, while the C-6'-O-H groups from molecules not in the cluster have gt conformations. Hybrid molecular mechanics/quantum mechanics calculations show \u003c1.2 kcal/mol strain for any of the small-molecule structures. Extrapolation of the NaI cellobiose geometry to a cellulose molecule gives a left-handed helix with 2.9 residues per turn. The energy map and small-molecule crystal structures imply that cellulose helices having 2.5 and 3.0 residues per turn are left-handed."}