Publications by authors named "Helton Jose Wiggers"

Healthcare-associated infections (HAIs) represent a global burden, leading to significant mortality and generating financial costs. One important cause of HAIs is the microbiological contamination of implantable medical devices. In this context, a novel antimicrobial drug-eluting system, based on chitosan and loaded with gentamicin, a broad-spectrum antibiotic, was developed.

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Natural polymer-based films, due to their favorable biological and mechanical properties, have demonstrated great potential as coatings for biomedical applications. Among them, chitosan films have been widely studied both as coating materials and as controlled drug release systems. Crosslinkers are often used to tune chitosan's crosslinking degree and thus to control the drug release kinetics.

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Trypanosomes are flagellated protozoa responsible for serious parasitic diseases that have been classified by the World Health Organization as tropical sicknesses of major importance. One important drug target receiving considerable attention is the enzyme glyceraldehyde-3-phosphate dehydrogenase from the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease (T. cruzi Glyceraldehyde-3-phosphate dehydrogenase (TcGAPDH); EC 1.

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The enzyme dihydroorotate dehydrogenase (DHODH) has been suggested as a promising target for the design of trypanocidal agents. We report here the discovery of novel inhibitors of Trypanosoma cruzi DHODH identified by a combination of virtual screening and ITC methods. Monitoring of the enzymatic reaction in the presence of selected ligands together with structural information obtained from X-ray crystallography analysis have allowed the identification and validation of a novel site of interaction (S2 site).

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Transthyretin (TTR) is a tetrameric beta-sheet-rich transporter protein directly involved in human amyloid diseases. It was recently found that the isoflavone genistein (GEN) potently inhibits TTR amyloid fibril formation (Green et al., 2005) and is therefore a promising candidate for TTR amyloidosis treatment.

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Trypanosoma cruzi dihydroorotate dehydrogenase (TcDHODH) catalyzes the oxidation of l-dihydroorotate to orotate with concomitant reduction of fumarate to succinate in the de novo pyrimidine biosynthetic pathway. Based on the important need to characterize catalytic mechanism of TcDHODH, we have tailored a protocol to measure TcDHODH kinetic parameters based on isothermal titration calorimetry. Enzymatic assays lead to Michaelis-Menten curves that enable the Michaelis constant (K(M)) and maximum velocity (V(max)) for both of the TcDHODH substrates: dihydroorotate (K(M)=8.

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