+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Trypanothione reductase from Trypanosoma cruzi. Catalytic properties of the enzyme and inhibition studies with trypanocidal compounds

Trypanothione reductase from Trypanosoma cruzi. Catalytic properties of the enzyme and inhibition studies with trypanocidal compounds

European Journal of Biochemistry 180(2): 267-272

Trypanothione reductase of Trypanosoma cruzi is a key enzyme in the antioxidant metabolism of the parasite. Here we report on the enzymic and pharmacological properties of trypanothione reductase using glutathionylspermidine disulfide as a substrate. 1. Both pH optimum (7.5) and the ionic strength optimum (at 30 mM) are unusually narrow for this enzyme. 40 mM Hepes, 1 mM EDTA, pH 7.5 was chosen as a standard assay buffer because in this system the kcat/Km ratio had the highest values for both natural substrates, glutathionylspermidine disulfide (2.65 x 10(6) M-1 s-1) and trypanothione disulfide (4.63 x 10(6) M-1 s-1). 2. Using the standardized assay, trypanothione reductase and the phylogenetically related host enzyme, human glutathione reductase, were studied as targets of inhibitors. Both enzymes, in their NADPH-reduced forms, were irreversibly modified by the cytostatic agent, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). Nifurtimox, the drug used in the treatment of Chagas' disease, is a stronger inhibitor of glutathione reductase (Ki = 40 microM) than of trypanothione reductase (IC50 = 200 microM). 3. Of the newly synthesized trypanocidal compounds [Henderson, G. B., Ulrich, P., Fairlamb, A. H., Rosenberg, I., Pereira, M., Sela, M. & Cerami, A. (1988) Proc. Natl Acad. Sci., 85, 5374-5378] a nitrofuran derivative, 2-(5-nitro-2-furanylmethylidene)-N,N'-[1,4-piperazinediylbis (1,3-propanediyl)]bishydrazinecarboximidamide tetrahydrobromide, was found to be a better inhibitor for trypanothione reductase (Ki = 0.5 microM) than for glutathione reductase (IC50 = 10 microM). A naphthoquinone derivative, 2,3-bis[3-(2-amidinohydrazono)-butyl]-1,4-naphthoquinone dihydrochloride, turned out to be both an inhibitor (IC50 = 1 microM) and an NADPH-oxidation-inducing substrate (Km = 14 microM). This effect was not observed with human glutathione reductase. Such compounds which lead to oxidative stress by more than one mechanism in the parasite are promising starting points for drug design based on the three-dimensional structures of glutathione and trypanothione reductases.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 007970627

Download citation: RISBibTeXText

PMID: 2647489

DOI: 10.1111/j.1432-1033.1989.tb14643.x

Related references

Crassiflorone derivatives that inhibit Trypanosoma brucei glyceraldehyde-3-phosphate dehydrogenase (TbGAPDH) and Trypanosoma cruzi trypanothione reductase (TcTR) and display trypanocidal activity. European Journal of Medicinal Chemistry 141: 138-148, 2017

Inhibition of Trypanosoma cruzi Trypanothione Reductase by Acridines: Kinetic Studies and StructureActivity Relationships. Journal of Medicinal Chemistry 42(26): 5448-5454, 1999

Inhibition of Trypanosoma cruzi trypanothione reductase by acridines: kinetic studies and structure-activity relationships. Journal of Medicinal Chemistry 42(26): 5448-5454, 1999

Trypanothione reductase from Trypanosoma cruzi. Purification and characterization of the crystalline enzyme. European Journal of Biochemistry 164(1): 123-128, 1987

Inhibition of Trypanosoma cruzi trypanothione reductase by crystal violet. Molecular and Biochemical Parasitology 67(2): 313-320, 1994

Design, synthesis and biological evaluation of new potent 5-nitrofuryl derivatives as anti-Trypanosoma cruzi agents. Studies of trypanothione binding site of trypanothione reductase as target for rational design. European Journal of Medicinal Chemistry 39(5): 421-431, 2004

Ajoene is an inhibitor and subversive substrate of human glutathione reductase and Trypanosoma cruzi trypanothione reductase: crystallographic, kinetic, and spectroscopic studies. Journal of Medicinal Chemistry 42(3): 364-372, 1999

Trypanosoma cruzi trypanothione reductase inhibitors: phenothiazines and related compounds modify experimental Chagas' disease evolution. Current Drug Targets. Cardiovascular and Haematological Disorders 2(1): 43-52, 2002

Trypanosoma cruzi Trypanothione Reductase Inhibitors: Phenothiazines and Related Compounds Modify Experimental Chagas Disease Evolution. Current Drug Target -Cardiovascular & Hematological Disorders 2(1): 43-52, 2002

Trypanothione Reductase and Superoxide Dismutase as Current Drug Targets for Trypanosoma cruzi: An Overview of Compounds with Activity against Chagas Disease. Current Medicinal Chemistry 24(11): 1066-1138, 2017

Overexpression of mutant trypanothione reductase genes in Trypanosoma cruzi reduces endogenous enzyme activity by formation of inactive heterodimers. FASEB Journal 7(7): A1173, 1993

Comparative structural, kinetic and inhibitor studies of Trypanosoma brucei trypanothione reductase with T. cruzi. Molecular and Biochemical Parasitology 169(1): 12-19, 2010

Rational design of selective ligands for trypanothione reductase from Trypanosoma cruzi. Structural effects on the inhibition by dibenzazepines based on imipramine. Journal of Enzyme Inhibition 12(3): 161-173, 1997

Potent and specific inhibitors of trypanothione reductase from Trypanosoma cruzi: bis(2-aminodiphenylsulfides) for fluorescent labeling studies. Bioorganic and Medicinal Chemistry 9(4): 837-846, 2001

Crystal structure of Trypanosoma cruzi trypanothione reductase in complex with trypanothione, and the structure-based discovery of new natural product inhibitors. Structure 7(1): 81-89, 1999