ITC Studies of Ribosome/Antibiotics Interactions.

The fight against multiresistant bacteria responsible for nosocomial diseases has recently been classified as an absolute priority by the World Health Organization. For some organisms, priority status has even been assessed as critical, as almost all currently available antibiotics are now inefficient against these "super-bacteria." Ribosome is a major target of several antibiotics, and extensive biochemical and structural studies led to a better understanding of the mechanism of action of drugs targeting translation (Blair et al., Nat Rev Microbiol 13:42-51, 2015; Lin et al., Annu Rev Biochem 87:451-478, 2018; Wilson, Nat Rev Microbiol 12:35-48, 2014; Yonath, Annu Rev Biochem 74:649-79, 2005). However, our knowledge regarding thermodynamic data of compounds targeting the ribosome, which are yet essential for a complete understanding of translation inhibition mechanisms by drugs, is still very poor.In this chapter we describe the use of ITC microcalorimetry to investigate the binding of bacterial ribosome to two antibiotics targeting the peptide tunnel: macrolides and proline-rich antimicrobial peptides (PrAMPs). This strategy yields reliable and artifact-free binding parameters for antibiotics and provides an original view on ribosome/antibiotics interactions.