HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Loladze, V. V. Articles by Makhatadze, G. I. Search for Related Content PubMed PubMed Citation Articles by Loladze, V. V. Articles by Makhatadze, G. I. Social Bookmarking                   What's this?

FOR THE RECORD

Removal of surface charge-charge interactions from ubiquitin leaves the protein folded and very stable

Department of Biochemistry and Molecular Biology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA

Reprint requests to: George I. Makhatadze, Department of Biochemistry and Molecular Biology, Penn State University College of Medicine, Hershey, PA 17033; e-mail: makhatadze{at}psu.edu; fax: (717) 531-7072.

The contribution of solvent-exposed charged residues to protein stability was evaluated using ubiquitin as a model protein. We combined site-directed mutagenesis and specific chemical modifications to first replace all Arg residues with Lys, followed by carbomylation of Lys-amino groups. Under the conditions in which all carboxylic groups are protonated (at pH 2), the chemically modified protein is folded and very stable (G = 18 kJ/mol). These results indicate that surface charge–charge interactions are not an essential fundamental force for protein folding and stability.

Keywords: Protein stability; chemical denaturation; chemical modification; energetics; electrostatic interactions; circular dichroism spectroscopy; balance of forces

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?