Sandbox Reserved 1121: Difference between revisions
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The C-reactive protein is a homopentamer of non-covalently bound subunits. Each subunit is a 25 Da protein consisting of 224 residues bound together. The secondary structure is formed of four α-helices and three β-sheets (five-stranded, three-stranded and seven-stranded).<ref>http://www.uniprot.org/uniprot/P02741</ref> The predominant structure is β-sheet <ref>http://www.unco.edu/nhs/Chemistry/faculty/dong/pub/pentraxin.pdf</ref> but short helical regions can be notice for residues 43 and 185.<ref name="kumar"/> Residues Glu197 and Lys123 in CRP form an intermolecular ion pair.<ref name="thompson" /> | The C-reactive protein is a homopentamer of non-covalently bound subunits. Each subunit is a 25 Da protein consisting of 224 residues bound together. The secondary structure is formed of four α-helices and three β-sheets (five-stranded, three-stranded and seven-stranded).<ref>http://www.uniprot.org/uniprot/P02741</ref> The predominant structure is β-sheet <ref>http://www.unco.edu/nhs/Chemistry/faculty/dong/pub/pentraxin.pdf</ref> but short helical regions can be notice for residues 43 and 185.<ref name="kumar"/> Residues Glu197 and Lys123 in CRP form an intermolecular ion pair.<ref name="thompson" /> | ||
=== Calcium binding-site === | === Calcium binding-site === | ||
CRP is a calcium dependent | CRP is a calcium dependent structure. Effectively, Ca2+ is required for PC binding, and more precisely for the formation of the PC binding site thanks to structural rearrangements. The protection against denaturation and proteolysis is performed through Ca2+ binding too. In the absence of Ca2+, hCRP is cleaved between Asn145 and Phe146 by nagarse protease, and between Phe146 and Glu147 by pronase. <ref name="ramadan">Ramadan, M. A. M., Shrive, A. K., Holden, D., Myles, D. A. A., Volanakis, J. E., Larry J.DeLucas, L. J., Greenhough, T. J. (2002), The three-dimensional structure of calcium-depleted human C-reactive protein from perfectly twinned crystals, Acta Cryst., D58 :992-1001</ref> | ||
=== PC binding site === | === PC binding site === | ||
