Carp parvalbumin

Nonrepetitive but well-defined structures of this type form many important features of enzyme active sites. In some cases, a particular arrangement of coil structure providing a specific type of functional site recurs in several functionally related proteins. The peptide loop that binds iron-sulfur clusters in both ferredoxin and high potential iron protein is one example. Another is the central loop portion of the E—F hand structure that binds a calcium ion in several calcium-binding proteins, including calmodulin, carp parvalbumin, troponin C, and the intestinal calcium-binding protein. This loop, shown in Figure 6.26, connects two short a-helices. The calcium ion nestles into the pocket formed by this structure. 

We now consider two calcium binding proteins, parvalbumin and troponin. The first, carp parvalbumin, is a small protein of known crystal structure.41 It binds two Ca2+ ions per molecule. One of the Ca2+ ions is essential for a folded structure to be maintained the second may be lost with a relatively small conformational change.42... 

Fig. 17. Model of the three-dimensional structure of carp parvalbumin showing the a-carbon backbone and a group of phenylalanine side chains, which form an enthalpically favorable set of aromatic-aromatic interactions and, to a large extent, define the core structure of this protein.

The complex NMR spectrum of calcium saturated carp parvalbumin and parvalbumin with 0.8 eq. of Yb3+ is shown in Fig. 10.35. The spectrum is more complex than lysozyme. When Yb3+ is added progressively to the protein, several of the proton resonances disappear from the original positions and several new resonances appear both upfield and downfield from the original diamagnetic positions. 

Fig. 10.35. 270 MHz H spectrum of (A) calcium saturated carp parvalbumin and (B) parvalbumin with 0.8...

Different from trigger proteins, parvalbumin and calbindinD9k frmction as calcium-buffer proteins. Calcium binding to both proteins does not lead to conformational change with an exposed hydrophobic surface. The structure of a carp parvalbumin was the first structure in the EF-hand protein family. It has two isoforms (a and fi) with very similar stmctures. Oncomodulin is the mammahan beta hnkage parvalbumin. The stmcture of parvalbumin comprises three helix-loop-helix motifs, called AB, CD, and EF initially (Figure 11). The calcium-binding loop in the first... 

Recently two structures of carp parvalbumin, both with a resolution of 1.6 A, were published. One of these stmctures is the native calcium-loaded form of the protein the second is the structure of parvalbumin in which Ca has been replaced by Cd +. No significant differences are observed upon replacement of calcium by cadmium. Cd has a nuclear spin of / =, making it much more amenable to NMR studies than the quadrupolar " Ca (/ = I). This study supports the use of Cd NMR as a tool for the study of calcium-binding proteins. ... 

Carp parvalbumin Virginia MWPC 28.2 61.0 54.3 C2 1.6 Swain, Kretsinger and... 

Bugajska-Schretter A, Grote M, Vangelista L, et al. (2000). Purification, biochemical, and immunological characterisation of a major food allergen different immunoglobulin E recognition of the apo- and calcium-bound forms of carp parvalbumin. Gut, 46 661-669. 

Swoboda I, Bugajska-Schretter A, Verdino P, et al. (2002). Recombinant carp parvalbumin, the major cross-reactive fish allergen a tool for diagnosis and therapy of fish allergy. J. Immunol, 168 4576 584. 

Swain, A. L., Kretsinger R. H. Amma, E.L. 1989, Refinement of native (calcium) and cadmium-substituted carp parvalbumin using X-Ray crystallogaphic data at 1.6 angstroms resolution. J. 

MOLECULAR GRAPHICS IN THE STUDY OF THE CALCIUM-BINDING SITES OF CARP PARVALBUMIN AND OTHER PROTEINS... 

We obtained atomic coordinates for modelling studies on carp parvalbumin, bovine-intestinal calcium binding protein, and also troponin-C (for which only the a-carbons are available at present) from the Brookhaven Protein Data Bank (October, 1985 release). The molecular graphics package used was Chemgraf (January, 1985 release), running on a VAX 11/780 at NUMAC, and the display was on a Sigma 5688 terminal. 

Carp parvalbumin contains two calcium-binding sequences called the CD and EF sites, established from the original X-ray structural determination of Kretsinger et al. The amino-acid sequences of the loops are shown in Table I, together with the Ca + binding site sequences for troponin C. The donor groups are underlined for the CD and EF sites. 

Lockhart, J. C. cuad H. Grey - Molecular graphics in the study of the calcium-binding sites of carp parvalbumin and other proteins 113... 

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