Molecular Mechanisms Of Chain Elongation, A Fundamental Process In Bacterial Biofilm Formation

Biofilm formation, the agglomeration of microorganisms on a surface, can account for greater than 80% of all human microbial infections. In a large group of Gram(+) and Gram(-) bacteria, a vital part of the biofilm scaffold is polysaccharide intercellular adhesin (PIA). To study the PIA synthase mechanism, 6-deoxy and 6-azido derivatives of GlcNAc, potential synthase inhibitors, were synthesized using optimized protection group chemistry. In vitro, expressed PIA synthase in E. coli membrane extracts was analysed by DispersinB and a malachite green phosphate assay. Biofilm microtitre well assays monitoring the cell growth and biofilm formation of E. coli and S. carnosus revealed the inhibition of biofilm formation by compound VP1 (IC50=1.48 mM). Whole cell MAS-NMR analysis of S. carnosus bacteria showed distinct 1H-NMR signals, useful for the analysis the PIA production. Together, the presented GlcNAc derivatives and the developed biological assays will facilitate the study the PIA synthase mechanism.MAS