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

J. Biol. Chem., Vol. 277, Issue 20, 17428-17437, May 17, 2002

This Article Full Text Full Text (PDF) All Versions of this Article: 277/20/17428    most recent M200650200v1 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Birolo, L. Articles by Marino, G. Search for Related Content PubMed PubMed Citation Articles by Birolo, L. Articles by Marino, G. Social Bookmarking                      What's this?

Structural Characterization of the M* Partly Folded Intermediate of Wild Type and P138A Aspartate Aminotransferase from Escherichia coli^*

Leila Birolo, Fabrizio Dal Piaz, Piero Pucci, and Gennaro Marino

From the Dipartimento di Chimica Organica e Biochimica, Università Federico II di Napoli, Complesso Universitario Monte Sant'Angelo, Via Cinthia, 80126 Napoli, Italy

A combination of spectroscopic techniques, hydrogen/deuterium exchange, and limited proteolysis experiments coupled to mass spectrometry analysis was used to depict the topology of the monomeric M* partly folded intermediate of aspartate aminotransferase from Escherichia coli in wild type (WT) as well as in a mutant form in which the highly conserved cis-proline at position 138 was replaced by a trans-alanine (P138A). Fluorescence analysis indicates that, although M* is an off-pathway intermediate in the folding of WT aspartate aminotransferase from E. coli, it seems to coincide with an on-pathway folding intermediate for the P138A mutant. Spectroscopic data, hydrogen/deuterium exchange, and limited proteolysis experiments demonstrated the occurrence of conformational differences between the two M* intermediates, with P138A-M* being conceivably more compact than WT-M*. Limited proteolysis data suggested that these conformational differences might be related to a different relative orientation of the small and large domains of the protein induced by the presence of the cis-proline residue at position 138. These differences between the two M* species indicated that in WT-M* Pro138 is in the cis conformation at this stage of the folding process. Moreover, hydrogen/deuterium exchange results showed the occurrence of few differences in the native N₂ forms of WT and P138A, the spectroscopic features and crystallographic structures of which are almost superimposable.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				A. Casbarra, L. Birolo, G. Infusini, F. Dal Piaz, M. Svensson, P. Pucci, C. Svanborg, and G. Marino Conformational analysis of HAMLET, the folding variant of human {alpha}-lactalbumin associated with apoptosis Protein Sci., May 1, 2004; 13(5): 1322 - 1330. [Abstract] [Full Text] [PDF]

				J. A. Oses-Prieto, M. T. Bengoechea-Alonso, A. Artigues, A. Iriarte, and M. Martinez-Carrion The Nature of the Rate-limiting Steps in the Refolding of the Cofactor-dependent Protein Aspartate Aminotransferase J. Biol. Chem., December 12, 2003; 278(50): 49988 - 49999. [Abstract] [Full Text] [PDF]