Short consensus repeats SCR3 and SCR1-3 are soluble recombinant proteins, consisting of the third and first three N-terminal domains of complement receptor 1, respectively, which retain some anti-complement activity. The conformational stabilities and folding/unfolding of SCR3 and SCR1-3 have been studied using circular dichroism and equilibrium and pre-equilibrium fluorescence spectroscopy. Denaturation by guanidinium hydrochloride (GdnHCl) is rapid and completely reversible. Reduction of disulphide bridges in the folded proteins by beta-mercaptoethanol leads to an increase in fluorescence intensity. The fluorescence intensity of the folded proteins is approximately 7.5% of that of the respective unfolded proteins. The data can be approximated to a two-state transition between native and denatured forms of the proteins. SCR3 has a conformational stability in water of 12-13 kJ/mol whereas that of SCR1-3 is 19.5-19.9 kJ/mol depending upon the technique utilized. The heat capacity change associated with the unfolding of SCR1-3 was obtained by a series of GdnHCl unfolding experiments over a range of temperatures and was found to be 6.6 kJ/K.mol or 33.8 J/K.mol(residue). The refolding process of SCR3 was found to be simple, described by a single exponential equation, whereas that of SCR1-3 was found to be complex and could be fitted to a double exponential equation indicating the presence of folding intermediates. Study holds ProTherm entries: 10884, 10885, 10886, 10887, 10888 Extra Details: -S-S- oxidized conformation; folding; human complement receptor 1;,SCR1-3 domains
ID: 28GdhFot3
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:41 p.m.
Version: 1
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Structure ID | Release Date | Resolution | Structure Title |
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1GKG | 2001-08-14T00:00:00+0000 | 0 | Structure Determination and Rational Mutagenesis reveal binding surface of immune adherence receptor, CR1 (CD35) |
1GKN | 2001-08-16T00:00:00+0000 | 0 | Structure Determination and Rational Mutagenesis reveal binding surface of immune adherence receptor, CR1 (CD35) |
1PPQ | 2003-06-17T00:00:00+0000 | 0 | NMR structure of 16th module of Immune Adherence Receptor, Cr1 (Cd35) |
2MCY | 2013-08-27T00:00:00+0000 | 0 | CR1 Sushi domains 2 and 3 |
2MCZ | 2013-08-27T00:00:00+0000 | 0 | CR1 Sushi domains 1 and 2 |
2Q7Z | 2007-06-08T00:00:00+0000 | 0 | Solution Structure of the 30 SCR domains of human Complement Receptor 1 |
5FO9 | 2015-11-18T00:00:00+0000 | 3.3 | Crystal Structure of Human Complement C3b in Complex with CR1 (CCP15- 17) |
Percent Identity | Matching Chains | Protein | Accession | Entry Name |
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100.0 | Complement receptor type 1 | P17927 | CR1_HUMAN |