TY  - JOUR
A1  - Harrington, John M.
A1  - Scelsi, Chris
A1  - Hartel, Andreas
A1  - Jones, Nicola G.
A1  - Engstler, Markus
A1  - Capewell, Paul
A1  - MacLeod, Annette
A1  - Hajduk, Stephen
T1  - Novel African Trypanocidal Agents: Membrane Rigidifying Peptides
JF  - PLoS One
N2  - The bloodstream developmental forms of pathogenic African trypanosomes are uniquely susceptible to killing by small hydrophobic peptides. Trypanocidal activity is conferred by peptide hydrophobicity and charge distribution and results from increased rigidity of the plasma membrane. Structural analysis of lipid-associated peptide suggests a mechanism of phospholipid clamping in which an internal hydrophobic bulge anchors the peptide in the membrane and positively charged moieties at the termini coordinate phosphates of the polar lipid headgroups. This mechanism reveals a necessary phenotype in bloodstream form African trypanosomes, high membrane fluidity, and we suggest that targeting the plasma membrane lipid bilayer as a whole may be a novel strategy for the development of new pharmaceutical agents. Additionally, the peptides we have described may be valuable tools for probing the biosynthetic machinery responsible for the unique composition and characteristics of African trypanosome plasma membranes.
KW  - depth
KW  - trypanosome lytic factor
KW  - signal peptides
KW  - cell surface
KW  - protein
KW  - brucei
KW  - environment
KW  - bilayers
KW  - binding
KW  - probes
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135179
VL  - 7
IS  - 9
ER  - 
TY  - JOUR
A1  - Koch, Oliver
A1  - Cappel, Daniel
A1  - Nocker, Monika
A1  - Jäger, Timo
A1  - Flohé, Leopold
A1  - Sotriffer, Christoph A.
A1  - Selzer, Paul M.
T1  - Molecular Dynamics Reveal Binding Mode of Glutathionylspermidine by Trypanothione Synthetase
JF  - PLoS ONE
N2  - The trypanothione synthetase (TryS) catalyses the two-step biosynthesis of trypanothione from spermidine and glutathione and is an attractive new drug target for the development of trypanocidal and antileishmanial drugs, especially since the structural information of TryS from Leishmania major has become available. Unfortunately, the TryS structure was solved without any of the substrates and lacks loop regions that are mechanistically important. This contribution describes docking and molecular dynamics simulations that led to further insights into trypanothione biosynthesis and, in particular, explains the binding modes of substrates for the second catalytic step. The structural model essentially confirm previously proposed binding sites for glutathione, ATP and two \(Mg^{2+}\) ions, which appear identical for both catalytic steps. The analysis of an unsolved loop region near the proposed spermidine binding site revealed a new pocket that was demonstrated to bind glutathionylspermidine in an inverted orientation. For the second step of trypanothione synthesis glutathionylspermidine is bound in a way that preferentially allows \(N^1\)-glutathionylation of \(N^8\)-glutathionylspermidine, classifying \(N^8\)-glutathionylspermidine as the favoured substrate. By inhibitor docking, the binding site for \(N^8\)-glutathionylspermidine was characterised as druggable.
KW  - purification
KW  - crithidia fasciulata
KW  - trypanosoma cruzi
KW  - RESP model
KW  - biosynthesis
KW  - chemotherapy
KW  - metabolism
KW  - brucei
KW  - system
KW  - leishmaniasis
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131070
VL  - 8
IS  - 2
ER  -