Studies of antibacterial activity (in vitro and in vivo) and mode of action for des-acyl tridecaptins (DATs).

Tridecaptins comprise a class of linear cationic lipopeptides with an N-terminal fatty acyl moiety. These 13-mer antimicrobial peptides consist of a combination of d- and l-amino acids, conferring increased proteolytic stability. Intriguingly, they are biosynthesized by non-ribosomal peptide synthetases in the same bacterial species that also produce the cyclic polymyxins displaying similar fatty acid tails.

The adaptability of the ion-binding site by the Ag(I)/Cu(I) periplasmic chaperone SilF.

The periplasmic chaperone SilF has been identified as part of an Ag(I) detoxification system in Gram-negative bacteria. Sil proteins also bind Cu(I) but with reported weaker affinity, therefore leading to the designation of a specific detoxification system for Ag(I). Using isothermal titration calorimetry, we show that binding of both ions is not only tighter than previously thought but of very similar affinities.

Modulating the poly-L-lysine structure through the control of the protonation-deprotonation state of L-lysine.

Designing the architecture of L-lysine-based polymeric structures is a highly challenging task that requires careful control of the amino acid reactive groups. Conventional processes to obtain branched polylysine need several steps and the addition of specific catalysts. In the present work, to gain a better understanding and control of the formation of L-lysine-based polymers, we have investigated the correlation between the protonation state of L-lysine and the corresponding hydrothermally grown structures.