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Westberry BP, Rio M, Waterland MR, Williams MAK. On the origin of optical rotation changes during the κ-carrageenan disorder-to-order transition. Carbohydr Polym 2024; 333:121975. [PMID: 38494229 DOI: 10.1016/j.carbpol.2024.121975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 02/08/2024] [Accepted: 02/20/2024] [Indexed: 03/19/2024]
Abstract
It is well established that solutions of both polymeric and oligomeric κ-carrageenan exhibit a clear change in optical rotation (OR), in concert with gel-formation for polymeric samples, as the solution is cooled in the presence of certain ions. The canonical interpretation - that this OR change reflects a 'coil-to-helix transition' in single chains - has seemed unambiguous; the solution- or 'disordered'-state structure has ubiquitously been assumed to be a 'random coil', and the helical nature of carrageenan in the solid-state was settled in the 1970s. However, recent work has found that κ-carrageenan contains substantial helical secondary structure elements in the disordered-state, raising doubts over the validity of this interpretation. To investigate the origins of the OR, density-functional theory calculations were conducted using atomic models of κ-carrageenan oligomers. Changes were found to occur in the predicted OR owing purely to dimerization of chains, and - together with the additional effects of slight changes in conformation that occur when separated helical chains form double-helices - the predicted OR changes are qualitatively consistent with experimental results. These findings contribute to a growing body of evidence that the carrageenan 'disorder-to-order' transition is a cooperative process, and have further implications for the interpretation of OR changes demonstrated by macromolecules in general.
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Affiliation(s)
- B P Westberry
- School of Natural Sciences, Massey University, Palmerston North, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand; Fonterra Research and Development Centre, Private Bag 11029, Dairy Farm Road, Palmerston North, New Zealand.
| | - M Rio
- National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand; Science Infrastructure (NeSI), Auckland, New Zealand
| | - M R Waterland
- School of Natural Sciences, Massey University, Palmerston North, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - M A K Williams
- School of Natural Sciences, Massey University, Palmerston North, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
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Collén PN, Lemoine M, Daniellou R, Guégan JP, Paoletti S, Helbert W. Enzymatic Degradation of κ-Carrageenan in Aqueous Solution. Biomacromolecules 2009; 10:1757-67. [DOI: 10.1021/bm9001766] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pi Nyvall Collén
- Université Pierre et Marie Curie, Paris VI, CNRS, Marine Plants and Biomolecules, UMR 7139, Station Biologique, BP 74, F29680 Roscoff Cedex, France, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, CS 50837, Avenue du General Leclerc, F-35708 Rennes Cedex 7, France, and Department of Life Sciences, University of Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
| | - Maud Lemoine
- Université Pierre et Marie Curie, Paris VI, CNRS, Marine Plants and Biomolecules, UMR 7139, Station Biologique, BP 74, F29680 Roscoff Cedex, France, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, CS 50837, Avenue du General Leclerc, F-35708 Rennes Cedex 7, France, and Department of Life Sciences, University of Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
| | - Richard Daniellou
- Université Pierre et Marie Curie, Paris VI, CNRS, Marine Plants and Biomolecules, UMR 7139, Station Biologique, BP 74, F29680 Roscoff Cedex, France, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, CS 50837, Avenue du General Leclerc, F-35708 Rennes Cedex 7, France, and Department of Life Sciences, University of Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
| | - Jean-Paul Guégan
- Université Pierre et Marie Curie, Paris VI, CNRS, Marine Plants and Biomolecules, UMR 7139, Station Biologique, BP 74, F29680 Roscoff Cedex, France, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, CS 50837, Avenue du General Leclerc, F-35708 Rennes Cedex 7, France, and Department of Life Sciences, University of Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
| | - Sergio Paoletti
- Université Pierre et Marie Curie, Paris VI, CNRS, Marine Plants and Biomolecules, UMR 7139, Station Biologique, BP 74, F29680 Roscoff Cedex, France, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, CS 50837, Avenue du General Leclerc, F-35708 Rennes Cedex 7, France, and Department of Life Sciences, University of Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
| | - William Helbert
- Université Pierre et Marie Curie, Paris VI, CNRS, Marine Plants and Biomolecules, UMR 7139, Station Biologique, BP 74, F29680 Roscoff Cedex, France, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, CS 50837, Avenue du General Leclerc, F-35708 Rennes Cedex 7, France, and Department of Life Sciences, University of Trieste, Via Giorgieri 1, I-34127 Trieste, Italy
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Stortz CA. Potential energy surfaces of carrageenan models: carrabiose, beta-(1 --> 4)-linked D-galactobiose, and their sulfated derivatives. Carbohydr Res 2002; 337:2311-23. [PMID: 12433495 DOI: 10.1016/s0008-6215(02)00173-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The adiabatic conformational surfaces of several beta-linked disaccharides, which correspond to the repeating structures of carrageenans, were calculated using the MM3 force-field. The studies were carried out on the disaccharide beta-D-Galp-(1 --> 4)-alpha-D-Galp and eight sulfated derivatives, as well as on carrabiose (beta-D-Galp-(1 --> 4)-3,6-An-alpha-D-Galp) and five sulfated derivatives. The presence of 3,6-anhydrogalactose does not change the main features of the maps, although it increases the flexibility of the glycosidic linkage. Sulfation neither produces a striking effect on the map shape, nor a shift on the global minimum, which always remains with psi (theta(C-1'-O-4-C-4C-5)) in trans orientation, and phi (theta(O-5'-C-1'-O-4-C-4)) with a value close to -80 degrees. This effect differs from that occurring on the alpha linkage of equivalent disaccharides, for which the sulfation pattern on the beta-galactose unit shifts the global minima to different positions. A reduction in the flexibility (originated in a deepening of the global minimum well) is observed by sulfation on position 2 of the beta-D-galactose unit, and by sulfation of position 6 of the alpha-D-galactose unit (when the beta-D-galactose unit is 4-sulfated). Within the compounds containing 3,6-anhydrogalactose, the effect of sulfation is even less noticeable. The calculated low-energy regions on carrabiose derivatives agree with X-ray diffraction data on carrageenan fibers and on peracetylated carrabiose dimethyl acetal, and with NOE calculations carried out on kappa-carrabiose.
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Affiliation(s)
- Carlos A Stortz
- Departamento de Química Orgánica-CIHIDECAR, Facultad de Ciencias Exactas y Naturales, UBA, Pab 2 Ciudad Universitaria, 1428 Buenos Aires, Argentina.
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Janaswamy S, Chandrasekaran R. Effect of calcium ions on the organization of iota-carrageenan helices: an X-ray investigation. Carbohydr Res 2002; 337:523-35. [PMID: 11890890 DOI: 10.1016/s0008-6215(02)00017-4] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
X-ray fiber diffraction analysis confirms that calcium iota-carrageenan forms a threefold, right-handed, half-staggered, parallel, double helix of pitch 26.42 A stabilized by interchain hydrogen bonds. According to the detailed structural results, three helices are packed in a trigonal unit cell (a=23.61 and c=13.21 A). Strong interactions between the sulfate groups of neighboring helices, mediated by calcium ions and water molecules, are responsible for stabilizing the three-dimensional structure.
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Affiliation(s)
- Srinivas Janaswamy
- Whistler Center for Carbohydrate Research, Food Science Building, Purdue University, West Lafayette, IN 47907-1160, USA
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Stroyan EP, Stevens ES. An improved model for calculating the optical rotation of simple saccharides. Carbohydr Res 2000; 327:447-53. [PMID: 10990030 DOI: 10.1016/s0008-6215(00)00072-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A calculational model for the optical rotation (OR) at the sodium D-line of simple saccharides has been developed that eliminates deficiencies of a previous model. Conformational conclusions based on the earlier model are not affected, as established by a recalculation of the OR phi,psi-map of methyl 3-O-(alpha-D-mannopyranosyl)-alpha-D-mannopyranoside. The model relocates the strong long-wavelength sigma-sigma* circular dichroism (CD) component, which is mainly responsible for the NaD OR from 160 to below 130 nm, where it is now known to occur. That correction allows future modeling of CD bands of different origins that appear in the 150-190 nm region. In order to demonstrate the utility of the revised model, it was applied to calculating the OR of methyl 3-O-(alpha-L-rhamnopyranosyl)-alpha-L-rhamnopyranoside. The results provide experimental support for conformational conclusions derived from a molecular mechanics study of that molecule.
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Affiliation(s)
- E P Stroyan
- Department of Chemistry, State University of New York, Binghamton 13902-6016, USA
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