Graphic data analysis and complex formation curves as modeling and optimization tools for characterization of Cu–(buffer)x–(OH)y systems involving BTP or BES in aqueous solution

Semisynthetic protein nanoreactor for single-molecule chemistry

The covalent chemistry of individual reactants bound within a protein pore can be monitored by observing the ionic current flow through the pore, which acts as a nanoreactor responding to bond-making and bond-breaking events. In the present work, we incorporated an unnatural amino acid into the α-hemolysin (αHL) pore by using solid-phase peptide synthesis to make the central segment of the polypeptide chain, which forms the transmembrane β-barrel of the assembled heptamer. The full-length αHL monomer was obtained by native chemical ligation of the central synthetic peptide to flanking recombinant polypeptides. αHL pores with one semisynthetic subunit were then used as nanoreactors for single-molecule chemistry. By introducing an amino acid with a terminal alkyne group, we were able to visualize click chemistry at the single-molecule level, which revealed a long-lived (4.5-s) reaction intermediate. Additional side chains might be introduced in a similar fashion, thereby greatly expanding the range of single-molecule covalent chemistry that can be investigated by the nanoreactor approach.

(Un)suitability of the use of pH buffers in biological, biochemical and environmental studies and their interaction with metal ions – a review

The present work reviews, discusses and update the metal complexation characteristics of thirty one buffers commercially available. Additionally, their impact on the biological systems is also presented and discussed.