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:  2014-09-10    
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    
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; EC 3.6.-/Acid Anhydride Hydrolases; EC; J41CSQ7QDS/Zinc

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

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