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

This Article 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Mattingly, J. R. Articles by Martinez-Carrion, M. Search for Related Content PubMed PubMed Citation Articles by Mattingly, J. R., Jr Articles by Martinez-Carrion, M. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 268, Issue 6, 3925-3937, 02, 1993

Protein folding in a cell-free translation system. The fate of the precursor to mitochondrial aspartate aminotransferase

JR Mattingly Jr, J Youssef, A Iriarte and M Martinez-Carrion
Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri, Kansas City 64110-2499.

The precursor to rat mitochondrial aspartate aminotransferase (pmAspAT) can be expressed in and purified from Escherichia coli as a fully active enzyme with remarkable trypsin resistance. Only two sites within the presequence are readily hydrolyzed (Martinez-Carrion, M., Altieri, F., Iriarte, A., Mattingly, J. R., Youssef, J., and Wu, T. (1990) Ann. N.Y. Acad. Sci. 585, 346-356). In contrast, pmAspAT freshly synthesized in rabbit reticulocyte lysate is significantly less resistant to proteolysis and is completely digested by trypsin. Extended incubation of the pmAspAT translation product slowly converts it to a species with qualitatively the same trypsin resistance as the purified pmAspAT. In addition, this species binds pyridoxal 5'-phosphate, exhibits catalytic activity, and loses its ability to be imported into mitochondria. This process appears to reflect protein folding. The rate of folding is unaffected by the addition of cofactor or the depletion of endogenous cofactor and is not significantly affected by the concentration of translation product in the reaction. Agents that decrease the availability of ATP partially inhibit the folding, whereas the sulfhydryl alkylating reagent N-ethylmaleimide and the detergent Triton X-100 completely prevent the conversion. Although the folding of pmAspAT in reticulocyte lysate is slow, folding is rapid once the translation product is sequestered within the mitochondria as the mature form of the enzyme. These results are presented as a model for the in vivo folding of pyridoxal-dependent, oligomeric mitochondrial precursors in the presence of cytoplasmic components and for the fate of true mitochondrial precursor proteins when not imported.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. Artigues, A. Iriarte, and M. Martinez-Carrion Binding to Chaperones Allows Import of a Purified Mitochondrial Precursor into Mitochondria J. Biol. Chem., July 5, 2002; 277(28): 25047 - 25055. [Abstract] [Full Text] [PDF]

				J. Zhou and H. Weiner The N-terminal portion of mature aldehyde dehydrogenase affects protein folding and assembly Protein Sci., August 1, 2001; 10(8): 1490 - 1497. [Abstract] [Full Text] [PDF]

				J. R. Mattingly Jr., C. Torella, A. Iriarte, and M. Martinez-Carrion Conformation of Aspartate Aminotransferase Isozymes Folding under Different Conditions Probed by Limited Proteolysis J. Biol. Chem., September 4, 1998; 273(36): 23191 - 23202. [Abstract] [Full Text] [PDF]

				B. Lain, A. Yanez, A. Iriarte, and M. Martinez-Carrion Aminotransferase Variants as Probes for the Role of the N-terminal Region of a Mature Protein in Mitochondrial Precursor Import and Processing J. Biol. Chem., February 20, 1998; 273(8): 4406 - 4415. [Abstract] [Full Text] [PDF]

				C. Torella, J. R. Mattingly Jr., A. Artigues, A. Iriarte, and M. Martinez-Carrion Insight into the Conformation of Protein Folding Intermediate(s) Trapped by GroEL J. Biol. Chem., February 13, 1998; 273(7): 3915 - 3925. [Abstract] [Full Text] [PDF]

				A. Artigues, A. Iriarte, and M. Martinez-Carrion Refolding Intermediates of Acid-unfolded Mitochondrial Aspartate Aminotransferase Bind to hsp70 J. Biol. Chem., July 4, 1997; 272(27): 16852 - 16861. [Abstract] [Full Text] [PDF]

				P. K. Hammen, M. Waltner, B. Hahnemann, T. S. Heard, and H. Weiner The Role of Positive Charges and Structural Segments in the Presequence of Rat Liver Aldehyde Dehydrogenase in Import into Mitochondria J. Biol. Chem., August 30, 1996; 271(35): 21041 - 21048. [Abstract] [Full Text] [PDF]

				M. Waltner and H. Weiner Conversion of a Nonprocessed Mitochondrial Precursor Protein into One That Is Processed by the Mitochondrial Processing Peptidase J. Biol. Chem., November 3, 1995; 270(44): 26311 - 26317. [Abstract] [Full Text] [PDF]

				B. Lain, A. Iriarte, J. R. Mattingly , Jr., J. I. Moreno, and M. Martinez-Carrion Structural Features of the Precursor to Mitochondrial Aspartate Aminotransferase Responsible for Binding to hsp70 J. Biol. Chem., October 20, 1995; 270(42): 24732 - 24739. [Abstract] [Full Text] [PDF]

				J. R. Mattingly Jr., A. Iriarte, and M. Martinez-Carrion Homologous Proteins with Different Affinities for groEL J. Biol. Chem., January 20, 1995; 270(3): 1138 - 1148. [Abstract] [Full Text] [PDF]

				F. Donate, A. J. Yanez, A. Iriarte, and M. Martinez-Carrion Interaction of the Precursor to Mitochondrial Aspartate Aminotransferase and Its Presequence Peptide with Model Membranes J. Biol. Chem., October 27, 2000; 275(44): 34147 - 34156. [Abstract] [Full Text] [PDF]