This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sealey-Cardona, M.
Right arrow Articles by González-Pacanowska, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sealey-Cardona, M.
Right arrow Articles by González-Pacanowska, D.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, June 2007, p. 2123-2129, Vol. 51, No. 6
0066-4804/07/$08.00+0     doi:10.1128/AAC.01454-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Kinetic Characterization of Squalene Synthase from Trypanosoma cruzi: Selective Inhibition by Quinuclidine Derivatives{triangledown}

Marco Sealey-Cardona,1 Simon Cammerer,2 Simon Jones,2 Luis M. Ruiz-Pérez,1 Reto Brun,3 Ian H. Gilbert,2 Julio A. Urbina,4 and Dolores González-Pacanowska1*

Instituto de Parasitología y Biomedicina López-Neyra, Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, s/n, 18100-Armilla, Granada, Spain,1 Welsh School of Pharmacy, Cardiff University, Redwood Building, King Edward VII Avenue, Cardif CF10 3XF, United Kingdom,2 Swiss Tropical Institute, Socinstrasse 57, P.O. Box, CH-4002 Basel, Switzerland,3 Laboratorio de Química Biológica, Centro de Bioquímica y Biofísica, Instituto Venezolano de Investigaciones Científicas, Altos de Pipe, Km. 11, Carretera Panamericana, Caracas 1020, Venezuela4

Received 20 November 2006/ Returned for modification 9 January 2007/ Accepted 13 March 2007

The biosynthesis of sterols is a major route for the development of antitrypanosomals. Squalene synthase (SQS) catalyzes the first step committed to the biosynthesis of sterols within the isoprenoid pathway, and several inhibitors of the enzyme have selective antitrypanosomal activity both in vivo and in vitro. The enzyme from Trypanosoma cruzi is a 404-amino-acid protein with a clearly identifiable membrane-spanning region. In an effort to generate soluble recombinant enzyme, we have expressed in Escherichia coli several truncated versions of T. cruzi SQS with a His tag attached to the amino terminus. Deletions of both the amino- and carboxyl-terminal regions generated active and soluble forms of the enzyme. The highest levels of soluble protein were achieved when 24 and 36 amino acids were eliminated from the amino and carboxyl regions, respectively, yielding a protein of 41.67 kDa. The Michaelis-Menten constants of the purified enzyme for farnesyl diphosphate and NAD (NADPH) were 5.25 and 23.34 µM, respectively, whereas the Vmax was 1,428.56 nmol min–1mg–1. Several quinuclidine derivatives with antiprotozoal activity in vitro were found to be selective inhibitors of recombinant T. cruzi SQS in comparative assays with the human enzyme, with 50% inhibitory concentration values in the nanomolar range. These data suggest that selective inhibition of T. cruzi SQS may be an efficient strategy for the development of new antitrypanosomal agents.

* Corresponding author. Mailing address: Instituto de Parasitología y Biomedicina "López-Neyra," Consejo Superior de Investigaciones Científicas, Avda. del Conocimiento s/n, Parque Tecnológico de Ciencias de la Salud, 18100-Armilla, Granada, Spain. Phone: 34 958 181621. Fax: 34 958 181633. E-mail: dgonzalez{at}ipb.csic.es

{triangledown} Published ahead of print on 19 March 2007.

Antimicrobial Agents and Chemotherapy, June 2007, p. 2123-2129, Vol. 51, No. 6
0066-4804/07/$08.00+0     doi:10.1128/AAC.01454-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Fernandes Rodrigues, J. C., Concepcion, J. L., Rodrigues, C., Caldera, A., Urbina, J. A., de Souza, W. (2008). In Vitro Activities of ER-119884 and E5700, Two Potent Squalene Synthase Inhibitors, against Leishmania amazonensis: Antiproliferative, Biochemical, and Ultrastructural Effects. Antimicrob. Agents Chemother. 52: 4098-4114 [Abstract] [Full Text]  
  • Lee, S., Poulter, C. D. (2008). Cloning, Solubilization, and Characterization of Squalene Synthase from Thermosynechococcus elongatus BP-1. J. Bacteriol. 190: 3808-3816 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»