100% complete assignment of non-labile 1H, 13C, and 15N signals for calcium-loaded calbindin D9k P43G

Here we present the 100% complete assignment chemical shift of non-labile 1H, 15N and 13C nuclei of Calbindin D9k P43G. The assignment includes all non-exchangeable side chain nuclei, including ones that are rarely reported, such as LysNζ as well as the termini. NMR experiments required to achieve truly complete assignments are discussed. To the best of our knowledge our assignments for Calbindin D9k extend beyond previous studies reaching near-completeness (Vis et al. in Biochem 33:14858–14870, 1994; Yamazaki et al. in J Am Chem Soc 116:6464–6465, 1994; Yamazaki et al. in Biochem 32:5656–5669, 1993b)

The Dynamics of Ca2+ Ions within the Solvation Shell of Calbindin D9k

The encounter of a Ca2+ ion with a protein and its subsequent binding to specific binding sites is an intricate process that cannot be fully elucidated from experimental observations. We have applied Molecular Dynamics to study this process with atomistic details, using Calbindin D9k (CaB) as a model protein. The simulations show that in most of the time the Ca2+ ion spends within the Debye radius of CaB, it is being detained at the 1st and 2nd solvation shells. While being detained near the protein, the diffusion coefficient of the ion is significantly reduced. However, due to the relatively long period of detainment, the ion can scan an appreciable surface of the protein. The enhanced propagation of the ion on the surface has a functional role: significantly increasing the ability of the ion to scan the protein's surface before being dispersed to the bulk. The contribution of this mechanism to Ca2+ binding becomes significant at low ion concentrations, where the intervals between successive encounters with the protein are getting longer. The efficiency of the surface diffusion is affected by the distribution of charges on the protein's surface. Comparison of the Ca2+ binding dynamics in CaB and its E60D mutant reveals that in the wild type (WT) protein the carboxylate of E60 function as a preferred landing-site for the Ca2+ arriving from the bulk, followed by delivering it to the final binding site. Replacement of the glutamate by aspartate significantly reduced the ability to transfer Ca2+ ions from D60 to the final binding site, explaining the observed decrement in the affinity of the mutated protein to Ca2+

Roadmap on dynamics of molecules and clusters in the gas phase

This roadmap article highlights recent advances, challenges and future prospects in studies of the dynamics of molecules and clusters in the gas phase. It comprises nineteen contributions by scientists with leading expertise in complementary experimental and theoretical techniques to probe the dynamics on timescales spanning twenty order of magnitudes, from attoseconds to minutes and beyond, and for systems ranging in complexity from the smallest (diatomic) molecules to clusters and nanoparticles. Combining some of these techniques opens up new avenues to unravel hitherto unexplored reaction pathways and mechanisms, and to establish their significance in, e.g. radiotherapy and radiation damage on the nanoscale, astrophysics, astrochemistry and atmospheric science

A combined optical pressure and velocity field measurement technique for single-bubble cavitation

Es wird eine neue kombinierte optische Messtechnik präsentiert, mit der sich Dichte- und Geschwindigkeitsfelder in transienten Strömungen mit Hilfe der Differential Interferometrie und microPIV bestimmen lassen. Zuerst wird die kombinierte Messtechnik etabliert und am Beispiel einer Temperatur getriebenen Wandströmung verifiziert. Eine wassergefüllte Küvette wird einseitig beheizt, sodass eine auftriebsgetriebene Zirkulationsströmung entsteht. Die resultierenden Temperatur- und Geschwindigkeitsfelder, werden mit Simulationsergebnissen verglichen. Die etablierte Messtechnik wird anschließend auf laserinduzierte Kavitationsblasen angewendet. Dabei werden kavitationsinduzierte Druckwellen und die dazugehörigen Blasendynamiken mit hoher Genauigkeit bestimmt. Auf der Basis von statistischen Auswertungen kann das Energiebudget von einzelnen Kavitationsblasen und die dazugehörige Druckwellenenergie auch für schwache Druckwellen bestimmt werden

The sources of strategic threats that are specific to high-tech innovative companies

W artykule zawarto wyniki badań sondażowych, dotyczących zagrożeń dla przedsiębiorstw innowacyjnych wysokich technologii oraz zagrożeń jako sytuacji kryzysowych oraz sformułowano wyjściowe, podstawowe rekomendacje dla doskonalenia zarządzania strategicznego w tych organizacjach. Wnioski i postulaty sformułowano na podstawie badań sondażowych, prowadzonych w trakcie realizacji projektu - grantu badawczego.The paper contains the results of surveys regarding the risks for innovative companies, high-tech and threats as emergencies and formulated output, basic recommendations for improving the strategic management of these organizations. Conclusions and proposals were formulated on the basis of surveys conducted during the project - a research grant

Mode of action of the staphylococcinlike peptide Pep 5: voltage-dependent depolarization of bacterial and artificial membranes.

The cationic staphylococcinlike peptide Pep 5 is shown to depolarize bacterial and planar lipid membranes in a voltage-dependent manner. An artificial valinomycin-induced potassium diffusion potential across the cytoplasmic membrane of Staphylococcus cohnii 22 was sufficient to promote Pep 5 action. Thus, evidence is provided that a membrane potential of sufficient magnitude is the only prerequisite for Pep 5 activity. The voltage dependence was elucidated by macroscopic conductance measurements with black lipid membranes. A threshold potential of about -90 to -100 mV, which was deduced from experiments with bacterial cells, could be confirmed. Single pores were resolved which often occur as short-lived bursts and fluctuate among different conductance levels. Pore diameters were calculated ranging from 0.1 to 1 nm. Succinylation of the lysine residues of Pep 5 resulted in prolonged pore lifetimes and maintenance of distinct conductance levels. However, the succinylated peptide required a higher threshold potential, approximately -150 mV, than the native peptide, which is probably the reason for the reduced activity of the modified peptide against intact gram-positive bacteria