2JWW
Calcium-free rat alpha-parvalbumin
Summary for 2JWW
| Entry DOI | 10.2210/pdb2jww/pdb |
| Descriptor | Parvalbumin alpha (1 entity in total) |
| Functional Keywords | alpha-parvalbumin, ef-hand protein, calcium-free, acetylation, muscle protein, phosphorylation, metal binding protein |
| Biological source | Rattus norvegicus (Rat) |
| Total number of polymer chains | 1 |
| Total formula weight | 11813.34 |
| Authors | Henzl, M.T.,Tanner, J.J. (deposition date: 2007-10-25, release date: 2008-08-12, Last modification date: 2024-05-29) |
| Primary citation | Henzl, M.T.,Tanner, J.J. Solution structure of Ca2+-free rat alpha-parvalbumin Protein Sci., 17:431-438, 2008 Cited by PubMed Abstract: Mammals express two parvalbumins-an alpha isoform and a beta isoform. In rat, the alpha-parvalbumin (alpha-PV) exhibits superior divalent ion affinity. For example, the standard free energies for Ca2+ binding differ by 5.5 kcal/mol in 0.15 M KCl (pH 7.4). High-resolution structures of the Ca2+-bound proteins provide little insight into this disparity, prompting a structural analysis of the apo-proteins. A recent analysis of rat beta-PV suggested that Ca2+ removal provokes substantial conformational changes-reorientation of the C, D, and E helices; reorganization of the hydrophobic core; reduced interdomain contact; and remodeling of the AB domain. The energetic penalty attendant to reversing these changes, it was suggested, could contribute to the attenuated divalent ion-binding signature of that protein. That hypothesis is supported by data presented herein, describing the solution structure and peptide backbone dynamics of Ca2+-free rat alpha-PV. In marked contrast to rat beta-PV, the apo- and Ca2+-loaded forms of the rat alpha isoform are quite similar. Significant structural differences appear to be confined to the loop regions of the molecule. This finding implies that the alpha-PV isoform enjoys elevated divalent ion affinity because the metal ion-binding events do not require major structural rearrangement and the concomitant sacrifice of binding energy. PubMed: 18218708DOI: 10.1110/ps.073318308 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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