Improved Tricyclic Inhibitors of Trypanothione Reductase by Screening and Chemical Synthesis

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Trypanothione reductase (TryR) is a key validated enzyme in the trypanothione-based redox metabolism of pathogenic trypanosomes and leishmania parasites. This system is absent in humans, being replaced with glutathione and glutathione reductase, and as such offers a target for selective inhibition. As part of a program to discover antiparasitic drugs, the LOPAC1280 library of 1266 compounds was screened against TryR and the top hits evaluated against glutathione reductase and T. brucei parasites. The top hits included a number of known tricyclic neuroleptic drugs along with other new scaffolds for TryR. Three novel druglike hits were identified and SAR studies on one of these using information from the tricyclic neuroleptic agents led to the discovery of a competitive inhibitor ( K _i=330 n m) with an improved potency against T. brucei (EC ₅₀=775 n m).

Related collections

Most cited references 62

Record: found
Abstract: found
Article: not found

Continuous cultivation of Trypanosoma brucei blood stream forms in a medium containing a low concentration of serum protein without feeder cell layers.

H Hirumi, K Hirumi (1989)

Blood stream forms (BSF) of Trypanosoma brucei brucei GUT at 3.1 were propagated in vitro in the absence of feeder layer cells at 37 C, using a modified Iscove's medium (HMI-18). The medium was supplemented with 0.05 mM bathocuproine sulfonate, 1.5 mM L-cysteine, 1 mM hypoxanthine, 0.2 mM 2-mercaptoethanol, 1 mM sodium pyruvate. 0.16 mM thymidine, and 20% (v/v) Serum Plus (SP) (Hazleton Biologics, Lenexa, Kansas). The latter contained a low level of serum proteins (13 micrograms/ml). Each primary culture was initiated by placing 3.5-4 x 10(6) BSFs isolated from infected mice in a flask containing 5 ml of the medium (HMI-9) supplemented with 10% fetal bovine serum (FBS) and 10% SP. The cultures were maintained by replacing the medium every 24 hr for 5-7 days. During this period, many BSFs died. However, from day 4 onward, long slender BSFs increased in number. On days 5-7, trypanosome suspensions were pooled and cell debris was removed by means of diethylaminoethyl cellulose (DE52) column chromatography. Blood stream forms then were collected by centrifugation, resuspended in fresh medium at 7-9 x 10(5)/ml, and transferred to new flasks. Subcultures were maintained by readjusting the BSF density to 7-9 x 10(5)/ml every 24 hr. Concentrations of FBS were reduced gradually at 5-7-day intervals by alternating the amounts of FBS and SP in HMI-9 with 5% FBS and 15% SP, with 2% FBS and 18% SP, and finally with 20% SP (HMI-18). By this method, 2-3 x 10(6) VSFs/ml were obtained consistently every 24 hr. for more than 80 days.(ABSTRACT TRUNCATED AT 250 WORDS)

0 comments Cited 307 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Kinetoplastids: related protozoan pathogens, different diseases.

Ken Stuart, Reto Brun, Simon Croft … (2008)

Kinetoplastids are a group of flagellated protozoans that include the species Trypanosoma and Leishmania, which are human pathogens with devastating health and economic effects. The sequencing of the genomes of some of these species has highlighted their genetic relatedness and underlined differences in the diseases that they cause. As we discuss in this Review, steady progress using a combination of molecular, genetic, immunologic, and clinical approaches has substantially increased understanding of these pathogens and important aspects of the diseases that they cause. Consequently, the paths for developing additional measures to control these "neglected diseases" are becoming increasingly clear, and we believe that the opportunities for developing the drugs, diagnostics, vaccines, and other tools necessary to expand the armamentarium to combat these diseases have never been better.

0 comments Cited 197 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Metabolism and functions of trypanothione in the Kinetoplastida.

Alan Fairlamb, A Cerami (1991)

Trypanosomatids differ from all other organisms in their ability to conjugate the sulfur-containing tripeptide, glutathione, and the polyamine, spermidine, to form trypanothione [N1,N8-bis(glutathionyl)spermidine]. Together with the NADPH-dependent flavoprotein, trypanothione reductase, the dithiol form of trypanothione provides an intracellular reducing environment in these parasites, substituting for glutathione and glutathione reductase found in the mammalian host. Trypanothione and its related enzymes are involved in defense against damage by oxidants, certain heavy metals, and possibly xenobiotics. Trypanothione and its metabolic precursor, glutathionylspermidine, are also implicated in the modulation of spermidine levels during growth. Several existing trypanocidal drugs interact with the trypanothione system, suggesting that trypanothione metabolism may be a good target for the development of new drugs. The purification and properties of three key enzymes (glutathionylspermidine synthetase, trypanothione synthetase, and trypanothione reductase) are discussed, and the catalytic mechanism, substrate-specificity, and the three-dimensional structure of trypanothione reductase are compared to that of glutathione reductase.

0 comments Cited 95 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): ChemMedChem

Journal ID (publisher-id): cmdc

Title: Chemmedchem

Publisher: WILEY-VCH Verlag

ISSN (Print): 1860-7179

ISSN (Electronic): 1860-7187

Publication date (Print): 03 August 2009

Volume: 4

Issue: 8

Pages: 1333-1340

Affiliations

[a ]simpleDr. J. L. Richardson, Dr. I. R. E. Nett, Dr. D. C. Jones, M. H. Abdille, Prof. I. H. Gilbert, Prof. A. H. Fairlamb Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee Dundee DD1 5EH, Scotland (UK), Fax: (+44) 1382-385-542

Article

DOI: 10.1002/cmdc.200900097

PMC ID: 2929371

PubMed ID: 19557801

SO-VID: a483d22b-00eb-45c1-840f-c2dbd3c7cffe

License:

Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

Improved Tricyclic Inhibitors of Trypanothione Reductase by Screening and Chemical Synthesis

Read this article at

Abstract

Related collections

Drug_transporters

Most cited references 62

Continuous cultivation of Trypanosoma brucei blood stream forms in a medium containing a low concentration of serum protein without feeder cell layers.

Kinetoplastids: related protozoan pathogens, different diseases.

Metabolism and functions of trypanothione in the Kinetoplastida.

Author and article information

Journal

Affiliations

Article

History

Categories

Comments

Comment on this article

Similar content 146

Cited by 18

Most referenced authors 987