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Intra- versus intermolecular interactions in monellin: contribution of surface charges to protein assembly

Xue, Wei-Feng, Szczepankiewicz, Olga, Bauer, Mikael C., Thulin, Eva, Linse, Sara (2006) Intra- versus intermolecular interactions in monellin: contribution of surface charges to protein assembly. Journal of Molecular Biology, 358 (5). pp. 1244-1255. ISSN 0022-2836. (doi:10.1016/j.jmb.2006.02.069) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/doi:10.1016/j.jmb.2006.02.069

Abstract

The relative significance of weak non-covalent interactions in biological context has been much debated. Here, we have addressed the contribution of Coulombic interactions to protein stability and assembly experimentally. The sweet protein monellin, a non-covalently linked heterodimeric protein, was chosen for this study because of its ability to spontaneously reconstitute from separated fragments. The reconstitution of monellin mutants containing large surface charge perturbations was compared to the thermostability of structurally equivalent single-chain monellin containing the same sets of mutations under varying salt concentrations. The affinity between monellin fragments is found to correlate with the thermostability of single chain monellin, indicating the involvement of the same underlying Coulombic interactions. This confirms that there are no principal differences in the interactions involved in folding and binding. Based on comparison with a previous mutational study involving hydrophobic core residues, the relative contribution of Coulombic interactions to stability and affinity is modest. However, the Coulombic perturbations only affect the association rates of reconstitution in contrast to perturbations involving hydrophobic residues, which affect primarily the dissociation rates. These results indicate that Coulombic interactions are likely to be of main importance for the association of protein assembly, relevant for functions of proteins.

Item Type: Article
DOI/Identification number: 10.1016/j.jmb.2006.02.069
Uncontrolled keywords: protein reconstitution; fragment complementation; electrostatic interactions; protein folding and binding; global analysis
Subjects: Q Science > QC Physics
Q Science > QD Chemistry
Q Science > QP Physiology (Living systems) > QP506 Molecular biology
Q Science > QP Physiology (Living systems) > QP517 Biochemistry
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Wei-Feng Xue
Date Deposited: 11 Jun 2013 13:06 UTC
Last Modified: 01 Aug 2019 10:35 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/34252 (The current URI for this page, for reference purposes)
Xue, Wei-Feng: https://orcid.org/0000-0002-6504-0404
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