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1oiz
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Alpha-tocopherol transfer protein (alpha-TTP) is a liver protein | + | Alpha-tocopherol transfer protein (alpha-TTP) is a liver protein responsible for the selective retention of alpha-tocopherol from dietary vitamin E, which is a mixture of alpha, beta, gamma, and delta-tocopherols and the corresponding tocotrienols. The alpha-TTP-mediated transfer of alpha-tocopherol into nascent VLDL is the major determinant of plasma alpha-tocopherol levels in humans. Mutations in the alpha-TTP gene have been detected in patients suffering from low plasma alpha-tocopherol and ataxia with isolated vitamin E deficiency (AVED). The crystal structure of alpha-TTP reveals two conformations. In its closed tocopherol-charged form, a mobile helical surface segment seals the hydrophobic binding pocket. In the presence of detergents, an open conformation is observed, which probably represents the membrane-bound form. The selectivity of alpha-TTP for RRR-alpha-tocopherol is explained from the van der Waals contacts occurring in the lipid-binding pocket. Mapping the known mutations leading to AVED onto the crystal structure shows that no mutations occur directly in the binding pocket. |
==Disease== | ==Disease== | ||
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[[Category: vitamin e]] | [[Category: vitamin e]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:18:19 2008'' |
Revision as of 12:18, 21 February 2008
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THE MOLECULAR BASIS OF VITAMIN E RETENTION: STRUCTURE OF HUMAN ALPHA-TOCOPHEROL TRANSFER PROTEIN
Contents |
Overview
Alpha-tocopherol transfer protein (alpha-TTP) is a liver protein responsible for the selective retention of alpha-tocopherol from dietary vitamin E, which is a mixture of alpha, beta, gamma, and delta-tocopherols and the corresponding tocotrienols. The alpha-TTP-mediated transfer of alpha-tocopherol into nascent VLDL is the major determinant of plasma alpha-tocopherol levels in humans. Mutations in the alpha-TTP gene have been detected in patients suffering from low plasma alpha-tocopherol and ataxia with isolated vitamin E deficiency (AVED). The crystal structure of alpha-TTP reveals two conformations. In its closed tocopherol-charged form, a mobile helical surface segment seals the hydrophobic binding pocket. In the presence of detergents, an open conformation is observed, which probably represents the membrane-bound form. The selectivity of alpha-TTP for RRR-alpha-tocopherol is explained from the van der Waals contacts occurring in the lipid-binding pocket. Mapping the known mutations leading to AVED onto the crystal structure shows that no mutations occur directly in the binding pocket.
Disease
Known disease associated with this structure: Ataxia with isolated vitamin E deficiency OMIM:[600415]
About this Structure
1OIZ is a Single protein structure of sequence from Homo sapiens with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The molecular basis of vitamin E retention: structure of human alpha-tocopherol transfer protein., Meier R, Tomizaki T, Schulze-Briese C, Baumann U, Stocker A, J Mol Biol. 2003 Aug 15;331(3):725-34. PMID:12899840
Page seeded by OCA on Thu Feb 21 14:18:19 2008
Categories: Homo sapiens | Single protein | Baumann, U. | Meier, R. | Schulze-Briese, C. | Stocker, A. | Tomizaki, T. | TRT | Ataxia | Aved | Tocopherol | Transfer protein | Transport | Vitamin e
