Oligosacàrids funcionals per síntesi enzimàtica. Nous enzims per a noves aplicacions

Davant l'interès creixent per les funcionalitats dels hidrats de carboni en l'organisme, la síntesi eficient d'oligosacàrids més complexos i polisacàrids esdevé una necessitat. Les estructures dels carbohidrats existents són el resultat de l'acció dels enzims glicosil transferases i els enzims glicosidases. La utilització d'aquests enzims in vitro és, per a la majoria de glicosil transferases, de moment, no rendible i per a les glicosidases, poc eficient, ja que la seva funció principal és la hidròlisi i, per tant, els rendiments de síntesi són baixos. El redisseny de glicosidases per tècniques d'enginyeria de proteïnes permet modificar l'activitat enzimàtica cap a la síntesi, eliminant la seva activitat hidrolítica. Aquests nous mutants, anomenats glicosintases, produeixen oligo i polisacàrids amb rendiments generalment quantitatius.Due to the increasing interest in functions of carbohydrates in the organism, efficient synthesis of more complex oligosaccharides and polysaccharides becomes a need. The carbohydrate structures that are present are the result of the action of glycosyl transferases enzymes and glycosidases enzymes. The use of these enzymes in vitro is, in the case of the majority of glycosyl transferases, by now not profitable, and in the case of the glycosidases is slightly efficient, because their main function is hydrolysis and then, yields in synthesis are low. The redesign of these glycosidases using protein engineering techniques allows to modify their enzymatic activity to the synthesis, eliminating the hydrolysis activity. These news mutants, called glycosynthases, afford oligo and polysaccharides generally in quantitative yields

Two-Component Systems of Mycobacterium tuberculosis as potential targets for drug development

Tuberculosis, caused by Mycobacterium tuberculosis, is a global health problem with approximately two million deaths every year. Furthermore, up to one-third of the world population is infected with latent form of this bacterium.Existing anti-tuberculosis therapies are directed against actively replicating bacteria, while there is no particular treatment for latent tuberculosis infection. Bacterial two-component systems (TCSs) are pleiotropic and play a central role in the adaptation of pathogenic bacteria to the environment prevailing within host tissues. TCS allow microorganisms to sense and respond to changes in many different environmental conditions therefore are consideredpotential pharmacological targets for the developmentof novel antimycobacterial drugs.In this work, we review the current knowledge of the TCSs of Mycobacterium tuberculosis. We discuss their role in bacterial pathogenesis and virulence. We pay special attention to the DosS/DosT/DosR TCS, emphasizing its importance in latent tuberculosis development