Effect of polysaccharide capsule of the microalgae staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique
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| Format: | Artículo científico |
| Langue: | en |
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Sociedade Brasileira de Física
2006
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| _version_ | 1876455856885727232 |
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| author | Cristina S. Freire-Nordi |
| author_facet | Cristina S. Freire-Nordi |
| contents | Effect of polysaccharide capsule of the microalgae staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique Cristina S. Freire-Nordi Armando A. H. Vieira Clovis R. Nakaie Otaciro R. Nascimento Física, Astronomía y Matemáticas EPR Algae capsules The existence of a mucilaginous envelope, sheath or capsule is usual in many desmids, but few data concerningits function are available. Previous studies of the transport function and permeation of molecules through thealgae capsules were done using the algae Spondylosium panduriforme and Nephrocytium lunatum, the ElectronParamagnetic Resonance (EPR) technique, and different spin labels. The results suggested that the capsule functionsas a selective diffusion medium. In the present work charged and uncharged molecules (spin labels groupA) and Staurastrum iversenii var. americanum (Desmids),whose alga presents a great mucilaginous capsule,were used. Charged nitroxide molecules similar to amino acids (spin labels group B) were also used allowing abetter understanding of the electrostatic effect in the permeation process across the capsule. The role of the cellcapsule in the solute diffusion was evaluated by determining the capsulated and decapsulated cell permeationtimes. The permeation times for all spin labels tested in the cells lacking capsules were always shorter thanthose containing this physical barrier. The decay times of spin labels group A observed for S. iversenii werecompared to other studied algae. The results regarding the diffusion of charged spin labels group B suggestedthat the interaction of cell capsule occurs more strongly with negatively charged molecules than with positivelycharged ones. The results obtained in this work with spin labels group A confirm that the capsule is an essentialstructure for the cell, and that due to the polar interactions with the spin labels, it plays an important role inthe selection of small molecules. Several parameters, mainly those of electrostatic nature, seem to control thepermeation across the algal capsules of spin labels group B, showing that structures which are similar to aminoacids could diffuse across the interior of the algal cell. 2006 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46436112 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.1A Vol.36 |
| format | Artículo científico |
| id | redalyc_46436112 |
| institution | Redalyc |
| language | en |
| publishDate | 2006 |
| publisher | Sociedade Brasileira de Física |
| spellingShingle | Effect of polysaccharide capsule of the microalgae staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique Cristina S. Freire-Nordi Física, Astronomía y Matemáticas EPR Algae capsules Effect of polysaccharide capsule of the microalgae staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique Cristina S. Freire-Nordi Armando A. H. Vieira Clovis R. Nakaie Otaciro R. Nascimento Física, Astronomía y Matemáticas EPR Algae capsules The existence of a mucilaginous envelope, sheath or capsule is usual in many desmids, but few data concerningits function are available. Previous studies of the transport function and permeation of molecules through thealgae capsules were done using the algae Spondylosium panduriforme and Nephrocytium lunatum, the ElectronParamagnetic Resonance (EPR) technique, and different spin labels. The results suggested that the capsule functionsas a selective diffusion medium. In the present work charged and uncharged molecules (spin labels groupA) and Staurastrum iversenii var. americanum (Desmids),whose alga presents a great mucilaginous capsule,were used. Charged nitroxide molecules similar to amino acids (spin labels group B) were also used allowing abetter understanding of the electrostatic effect in the permeation process across the capsule. The role of the cellcapsule in the solute diffusion was evaluated by determining the capsulated and decapsulated cell permeationtimes. The permeation times for all spin labels tested in the cells lacking capsules were always shorter thanthose containing this physical barrier. The decay times of spin labels group A observed for S. iversenii werecompared to other studied algae. The results regarding the diffusion of charged spin labels group B suggestedthat the interaction of cell capsule occurs more strongly with negatively charged molecules than with positivelycharged ones. The results obtained in this work with spin labels group A confirm that the capsule is an essentialstructure for the cell, and that due to the polar interactions with the spin labels, it plays an important role inthe selection of small molecules. Several parameters, mainly those of electrostatic nature, seem to control thepermeation across the algal capsules of spin labels group B, showing that structures which are similar to aminoacids could diffuse across the interior of the algal cell. 2006 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46436112 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.1A Vol.36 |
| title | Effect of polysaccharide capsule of the microalgae staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique |
| topic | Física, Astronomía y Matemáticas EPR Algae capsules |
| url | https://www.redalyc.org/articulo.oa?id=46436112 |