Riboflavin synthase from Brucella as target for structure-based drug design (Poster)

LUCÍA M. POTH; MARÍA I. SERER; MARÍA L. CERUTTI; MARIELA DEL C. CARRICA; FERNANDO A. GOLDBAUM; SEBASTIÁN KLINKE

San Luis

Congreso; XII Reunión Anual de la Asociación Argentina de Cristalografía (AACr); 2016

Asociación Argentina de Cristalografía (AACr)

Theenzyme Riboflavin synthase (RS) from Brucella abortus catalyzes the last stepin riboflavin biosynthesis (vitamin B2), being an interesting target for thedevelopment of inhibitors against this pathogenic bacterium, since Brucella isunable to take exogenous vitamin B2 with efficiency and relies entirely on itsown biosynthesis. RS is an intrinsically flexible homotrimer with a molecularweight of 70 kDa. In our lab, we solved the crystal structure of RS as apo-enzymeand also in the presence of bound products and product analogue inhibitors.Recently, we have started a structure-based drug design project on RS, whosefirst step corresponded to the high-throughput search of inhibitors using adrug-like small molecule library. Several hits have been found and we areactively working in obtaining the three-dimensional structures of RS in complexwith these inhibitors, with the aim of improving affinities, contacts andcomplementarity by chemical modification of these compounds in a second step. Inthis work we will present our latest results in RS crystal growth andoptimization, exploring different strategies for the introduction of theligands (co-crystallization, soaking) and testing different precipitants, pHvalues and additives to minimize the flexibility of the protein in the crystallattice. Additionally, diffraction data from our Bruker in-house single crystalX-ray diffractometer and from the PROXIMA 1 and 2 beamlines (SOLEILsynchrotron, France) will be presented and analyzed.