Receptor-associated protein (RAP) has two high-affinity binding sites for the low-density lipoprotein receptor-related protein (LRP): consequences for the chaperone functions of RAP
| Autor: | Christine Schar, Peter G.W. Gettins, Jan K. Jensen, Klavs Dolmer |
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| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Models
Molecular Protein Folding CRxyz LRP fragment containing domains CRx CRy and CRz Protein Conformation 2-ME 2-mercaptoethanol LDLR-associated protein (LRP) D1 D2 and D3 first second and third domains of RAP Biochemistry 0302 clinical medicine Protein structure receptor-associated protein (RAP) GST glutathione transferase (V)LDLR (very-) low-density lipoprotein receptor chaperone LDL-Receptor Related Protein-Associated Protein Receptor 0303 health sciences biology Chemistry ITC isothermal titration calorimetry Temperature Hydrogen-Ion Concentration Protein folding lipids (amino acids peptides and proteins) (CR)x LRP fragment containing x CR domains Low Density Lipoprotein Receptor-Related Protein-1 Research Article YWTD domain RAP receptor-associated protein LDL-receptor-related protein-associated protein ligand release TEV tobacco etch virus ER endoplasmic reticulum 03 medical and health sciences Binding site CR complement-like repeat Molecular Biology 030304 developmental biology Binding Sites Endoplasmic reticulum fungi CRxy LRP fragment containing domains CRx and CRy Cell Biology LDL-Receptor Related Protein 1 Protein Structure Tertiary body regions Kinetics Spectrometry Fluorescence Chaperone (protein) LDL receptor biology.protein IPTG isopropyl β-D-thiogalactoside LA34 third and fourth CR domains from the ligand-binding cluster of LDLR LRP low-density lipoprotein receptor-related protein sense organs low-density lipoprotein receptor (LDLR) 030217 neurology & neurosurgery Molecular Chaperones |
| Zdroj: | Biochemical Journal Jensen, J K, Dolmer, K, Schar, C & Gettins, P G W 2009, ' Receptor-associated protein (RAP) has two high-affinity binding sites for the low-density lipoprotein receptor-related protein (LRP): consequences for the chaperone functions of RAP ', Biochemical Journal, vol. 421, no. 2, pp. 273-82 . https://doi.org/10.1042/BJ20090175 |
| ISSN: | 1470-8728 0264-6021 |
| Popis: | RAP (receptor-associated protein) is a three domain 38 kDa ER (endoplasmic reticulum)-resident protein that is a chaperone for the LRP (low-density lipoprotein receptor-related protein). Whereas RAP is known to compete for binding of all known LRP ligands, neither the location, the number of binding sites on LRP, nor the domains of RAP involved in binding is known with certainty. We have systematically examined the binding of each of the three RAP domains (D1, D2 and D3) to tandem and triple CRs (complement-like repeats) that span the principal ligand-binding region, cluster II, of LRP. We found that D3 binds with low nanomolar affinity to all (CR)2 species examined. Addition of a third CR domain increases the affinity for D3 slightly. A pH change from 7.4 to 5.5 gave only a 6-fold increase in Kd for D3 at 37 degrees C, whereas temperature change from 22 degrees C to 37 degrees C has a similar small effect on affinity, raising questions about the recently proposed D3-destabilization mechanism of RAP release from LRP. Surprisingly, and in contrast to literature suggestions, D1 and D2 also bind to most (CR)2 and (CR)3 constructs with nanomolar affinity. Although this suggested that there might be three high-affinity binding sites in RAP for LRP, studies with intact RAP showed that only two binding sites are available in the intact chaperone. These findings suggest a new model for RAP to function as a folding chaperone and also for the involvement of YWTD domains in RAP release from LRP in the Golgi. |
| Databáze: | OpenAIRE |
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