Document Detail

Overexpression of a Zn2+-sensitive soluble exopolyphosphatase from Trypanosoma cruzi depletes polyphosphate and affects osmoregulation.
MedLine Citation:
PMID:  17827150     Owner:  NLM     Status:  MEDLINE    
We report the cloning, expression, purification, and characterization of the Trypanosoma cruzi exopolyphosphatase (TcPPX). The product of this gene (TcPPX), has 383 amino acids and a molecular mass of 43.1 kDa. TcPPX differs from most exopolyphosphatases in its preference for short-chain polyphosphate (poly P). Heterologous expression of TcPPX in Escherichia coli produced a functional enzyme that had a neutral optimum pH and was dramatically inhibited by low concentrations of Zn2+, high concentrations of basic amino acids (lysine and arginine), and heparin. TcPPX is a processive enzyme and does not hydrolyze ATP, pyrophosphate, or p-nitrophenyl phosphate, although it hydrolyzes guanosine 5'-tetraphosphate very efficiently. Overexpression of TcPPX resulted in a dramatic decrease in total short-chain poly P and partial decrease in long-chain poly P. This was accompanied by a delayed regulatory volume decrease after hyposmotic stress. These results support the role of poly P in T. cruzi osmoregulation.
Jianmin Fang; Felix A Ruiz; Melissa Docampo; Shuhong Luo; Juliany C F Rodrigues; Lucimar S Motta; Peter Rohloff; Roberto Docampo
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2007-09-07
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  282     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  2007 Nov 
Date Detail:
Created Date:  2007-10-29     Completed Date:  2007-12-13     Revised Date:  2011-04-21    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  32501-10     Citation Subset:  IM    
Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Paul D. Coverdell Biomedical and Health Sciences Center, Athens, Georgia 30602, USA.
Data Bank Information
Bank Name/Acc. No.:
GENBANK/AF545106;  AY178275
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MeSH Terms
Acid Anhydride Hydrolases / chemistry,  genetics,  metabolism*
Amino Acid Sequence
Cloning, Molecular
Molecular Sequence Data
Polyphosphates / metabolism*
Protein Structure, Tertiary
Protozoan Proteins / chemistry,  genetics,  metabolism*
Recombinant Proteins / chemistry,  genetics,  metabolism
Sequence Homology
Trypanosoma cruzi / enzymology*
Water-Electrolyte Balance*
Zinc / metabolism*
Grant Support
Reg. No./Substance:
0/Polyphosphates; 0/Protozoan Proteins; 0/Recombinant Proteins; 7440-66-6/Zinc; EC 3.6.-/Acid Anhydride Hydrolases; EC

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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