scholarly journals Further Insight into Crystal Structures of Escherichia coli IspH/LytB in Complex with Two Potent Inhibitors of the MEP Pathway: A Starting Point for Rational Design of New Antimicrobials

ChemBioChem ◽  
2017 ◽  
Vol 18 (21) ◽  
pp. 2137-2144 ◽  
Author(s):  
Franck Borel ◽  
Elodie Barbier ◽  
Sergiy Krasutsky ◽  
Karnjapan Janthawornpong ◽  
Philippe Chaignon ◽  
...  
Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1037
Author(s):  
Jorge González-Bacerio ◽  
Irina Arocha ◽  
Mirtha Elisa Aguado ◽  
Yanira Méndez ◽  
Sabrina Marsiccobetre ◽  
...  

Chagas disease, caused by the kinetoplastid parasite Trypanosoma cruzi, is a human tropical illness mainly present in Latin America. The therapies available against this disease are far from ideal. Proteases from pathogenic protozoan have been considered as good drug target candidates. T. cruzi acidic M17 leucyl-aminopeptidase (TcLAP) mediates the major parasite’s leucyl-aminopeptidase activity and is expressed in all parasite stages. Here, we report the inhibition of TcLAP (IC50 = 66.0 ± 13.5 µM) by the bestatin-like peptidomimetic KBE009. This molecule also inhibited the proliferation of T. cruzi epimastigotes in vitro (EC50 = 28.1 ± 1.9 µM) and showed selectivity for the parasite over human dermal fibroblasts (selectivity index: 4.9). Further insight into the specific effect of KBE009 on T. cruzi was provided by docking simulation using the crystal structure of TcLAP and a modeled human orthologous, hLAP3. The TcLAP-KBE009 complex is more stable than its hLAP3 counterpart. KBE009 adopted a better geometrical shape to fit into the active site of TcLAP than that of hLAP3. The drug-likeness and lead-likeness in silico parameters of KBE009 are satisfactory. Altogether, our results provide an initial insight into KBE009 as a promising starting point compound for the rational design of drugs through further optimization.


2018 ◽  
Vol 6 (2) ◽  
pp. 99-115
Author(s):  
Borislav Marušić ◽  
Sanda Katavić-Čaušić

Abstract The aim of this paper is to research the word class adjective in one sequence of the ESP: Business English, more precisely English business magazines online. It is an empirical study on the corpus taken from a variety of business magazines online. The empirical analysis allows a comprehensive insight into the word class adjective in this variety of Business English and makes its contribution to English syntax, semantics and word formation. The syntactic part analyses the adjective position in the sentence. The semantic part of the study identifies the most common adjectives that appear in English business magazines online. Most of the analysis is devoted to the word formation of the adjectives found in the corpus. The corpus is analysed in such a way that it enables its division into compounds, derivatives and conversions. The results obtained in this way will give a comprehensive picture of the word class adjective in this type of Business English and can act as a starting point for further research of the word class adjective.


1956 ◽  
Vol 11 (11) ◽  
pp. 920-934b
Author(s):  
Konrad Schubert

In determining structures we use physical propositions in order to find a likely crystal structure. The same propositions are of value for the ordering of known structures into a natural system. The atomic radii form such a proposition. Another proposition is contained in the spatial correlation of electrons in the electron gas. The question is, whether this correlation is of influence on the crystal structure or not. To gain a first insight into this question, it is useful to know whether the crystal structures are physically compatible with a certain spatial correlation of electrons. Some qualitative rules are given to assess the physical possibility of a spatial correlation of electrons in a crystal structure. For the crystal structures of some chemical elements proposals for electron correlation are given. These proposals account for rationalities existing between some lattice constants, e. g. the axial ratios of the hexagonal close packed structures of Co and Zn. The proposals are also applicable to some binary compounds. With regard to these commensurabilities, it seems possible that the examination of the spatial correlation of electrons may lead to a better understanding of the crystal-chemical empiry.


2009 ◽  
Vol 390 (2) ◽  
pp. 196-207 ◽  
Author(s):  
Elena Seiradake ◽  
Weimin Mao ◽  
Vincent Hernandez ◽  
Stephen J. Baker ◽  
Jacob J. Plattner ◽  
...  

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Erik H. Klontz ◽  
Adam D. Tomich ◽  
Sebastian Günther ◽  
Justin A. Lemkul ◽  
Daniel Deredge ◽  
...  

ABSTRACT Fosfomycin exhibits broad-spectrum antibacterial activity and is being reevaluated for the treatment of extensively drug-resistant pathogens. Its activity in Gram-negative organisms, however, can be compromised by expression of FosA, a metal-dependent transferase that catalyzes the conjugation of glutathione to fosfomycin, rendering the antibiotic inactive. In this study, we solved the crystal structures of two of the most clinically relevant FosA enzymes: plasmid-encoded FosA3 from Escherichia coli and chromosomally encoded FosA from Klebsiella pneumoniae (FosAKP). The structure, molecular dynamics, catalytic activity, and fosfomycin resistance of FosA3 and FosAKP were also compared to those of FosA from Pseudomonas aeruginosa (FosAPA), for which prior crystal structures exist. E. coli TOP10 transformants expressing FosA3 and FosAKP conferred significantly greater fosfomycin resistance (MIC, >1,024 μg/ml) than those expressing FosAPA (MIC, 16 μg/ml), which could be explained in part by the higher catalytic efficiencies of the FosA3 and FosAKP enzymes. Interestingly, these differences in enzyme activity could not be attributed to structural differences at their active sites. Instead, molecular dynamics simulations and hydrogen-deuterium exchange experiments with FosAKP revealed dynamic interconnectivity between its active sites and a loop structure that extends from the active site of each monomer and traverses the dimer interface. This dimer interface loop is longer and more extended in FosAKP and FosA3 than in FosAPA, and kinetic analyses of FosAKP and FosAPA loop-swapped chimeric enzymes highlighted its importance in FosA activity. Collectively, these data yield novel insights into fosfomycin resistance that could be leveraged to develop new strategies to inhibit FosA and potentiate fosfomycin activity.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Wataru Shihoya ◽  
Tamaki Izume ◽  
Asuka Inoue ◽  
Keitaro Yamashita ◽  
Francois Marie Ngako Kadji ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document