Normal salts are well behaved and have uniform action (i.e. in the one direction) of the collapse-swelling equilibrium. So the more salt we add, the stronger the effect. However, guanidinium thiocyanate (GndSCN) is special and collapses the polymer at first dose, but but reswells the the polymer at higher salt concentrations.
Our story, which was recently published in JACS was presented at Spring-Meeting of DPG in Dresden 2017 – pdf with presentation.
Why are some salts more active in protein precipitation than others? Why do we find always the same salt series in a plethora of effects. In our recent Feature Article we provide the answers and summarize the knowledge on salt-specific effects, based on the combination of thermodynamic and spectroscopic methods with computational modelling and theory in the last 10 year. link
Already pure guanidinum chloride (GndCl) solution is remarkable. It contains a significant fraction of guanidinium cations in direct contact, a typically rare feature, which is counterintuitive (on electrostatic grounds) link.
Proteins are unfolded and solutes destabilized in concentrated solutions of GndCl in general. Indeed GndCl is, after urea, the second most common denaturing agent. In the recent article we present different faces of guanidinium action, stabilizing as well as destabilizing which are intimately connected with the anion in action. This work is a joint experimental (spectroscopy & thermodynamics) computational (simulations & theory) study. link
During this lightning talk (3 minutes + 2 for discussion) I presented Smart materials to a non-scientific audience. Enjoy the YouTube video or check the presentation (both are in Czech only, sorry).
Other short (or not so short) talks from the conference can be found on https://krecon.cz/prezentace/
The award seeks to encourage young scientists to engage themselves in the scientific examination of the multifaceted issues and questions specifically related to the Danube and to stimulate the specific community in the Danube Region. Universities, Academies of Scincences and research Institutions in all 14 countries of the Danube Region have been encouraged to nominate suitable and promising candidates that have been assessed by an international expert jury. The highest ranked candidate of each of the countries that submitted eligible nominations was awarded with the prize. (Krems 9/11/2016)
More details are available via this link.
This year, we made an attempt to merge the Theoretical chemistry seminar at IOCB with those at Physical chemistry at UCT. This collaboration results in twelve great lectures with local as well as international/foreign speakers.
Time: Fridays 15.00
Place: A402 (UCT), B4 (B.4.29, IOCB)
The LCST is not restricted to macromolecular systems only, but can be found even in binary mixtures, although rarely. In this work our colleagues found and ionic-liquid, which has LCST (~45°C) , when mixed with acetone. It was found, that LCST is not present in any of other 10 organic solvents tested, and also not when anion of ionic liquid is modified. Moreover the LCST is very sensitive to the addition of supramolecular hosts, such as pillararene or crown ether, which decrease/or/increase the LCST by ~10°C, when present already below 100mM concentration.
The article is open-access thanks to the donation of the library FU Berlin. link