Comparative structural, kinetic and inhibitor studies of Trypanosoma brucei trypanothione reductase with T. cruzi

Autor: Alan H. Fairlamb, Wing-Huen A. Chow, Deuan C. Jones, Sandra L. Oza, Antonio Ariza
Jazyk: angličtina
Rok vydání: 2010
Předmět:
T(S)2
trypanothione disulphide
Trypanothione metabolism
DTNB
Trypanosoma cruzi
Glutathione reductase
Trypanosoma brucei brucei
Trypanothione
Molecular Conformation
Protozoan Proteins
Trypanosoma brucei
01 natural sciences
Trypanosome
Article
Substrate Specificity
DTNB
5
5′-dithio-bis(2-nitrobenzoic acid)
03 medical and health sciences
chemistry.chemical_compound
HAT
human African trypanosomiasis
Oxidoreductase
Enzyme Stability
parasitic diseases
NADH
NADPH Oxidoreductases
Enzyme Inhibitors
TryR
trypanothione reductase
Molecular Biology
030304 developmental biology
chemistry.chemical_classification
0303 health sciences
biology
010405 organic chemistry
Drug discovery
biology.organism_classification
3. Good health
0104 chemical sciences
Kinetics
Trypanothione-disulfide reductase
Enzyme
Biochemistry
chemistry
Thiol
Enzymology
Parasitology
Zdroj: Molecular and Biochemical Parasitology
ISSN: 1872-9428
0166-6851
Popis: As part of a drug discovery programme to discover new treatments for human African trypanosomiasis, recombinant trypanothione reductase from Trypanosoma brucei has been expressed, purified and characterized. The crystal structure was solved by molecular replacement to a resolution of 2.3A and found to be nearly identical to the T. cruzi enzyme (root mean square deviation 0.6A over 482 Calpha atoms). Kinetically, the K(m) for trypanothione disulphide for the T. brucei enzyme was 4.4-fold lower than for T. cruzi measured by either direct (NADPH oxidation) or DTNB-coupled assay. The K(m) for NADPH for the T. brucei enzyme was found to be 0.77microM using an NADPH-regenerating system coupled to reduction of DTNB. Both enzymes were assayed for inhibition at their respective S=K(m) values for trypanothione disulphide using a range of chemotypes, including CNS-active drugs such as clomipramine, trifluoperazine, thioridazine and citalopram. The relative IC(50) values for the two enzymes were found to vary by no more than 3-fold. Thus trypanothione reductases from these species are highly similar in all aspects, indicating that they may be used interchangeably for structure-based inhibitor design and high-throughput screening.
Databáze: OpenAIRE
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