Abstract: We studied the effect of submicromolar concentrations of cytochrome c (cyt c) on the phase behavior of ternary lipid membranes composed of charged dioleoylphosphatidylglycerol, egg sphingomyelin and cholesterol. The protein was found to induce micron-sized domains in membranes belonging to the single-fluid-phase region of the protein-free ternary mixture and, as a result, to expand the region of coexistence of liquid ordered (L_o) and liquid disordered (L_d) phases. Direct observations on individual vesicles revealed that protein adsorption increases the area of L_d domains.

Abstract: This work is concerned with the surface modification of fluorescent silica nanoparticles by a monoclonal antibody (M75) and the specific bioadhesion of such particles to surfaces containing the PG domain of carbonic anhydrase IX (CA IX), which is a trans-membrane protein specifically expressed on the surfaces of several tumor cell lines. The adhesion strength of antibody-bearing silica nanoparticles to antigen-bearing surfaces was investigated under laminar flow conditions in a microfluidic cell and compared to the adhesion of unmodified silica nanoparticles and nanoparticles coupled with an unspecific antibody.

Abstract: The biological properties of a protein critically depend on its conformation, which can vary as a result of changes in conditions such as pH or following the addition of various substances. Being able to reliably assess the quality of protein structures under various conditions is therefore of crucial importance. Infrared (IR) spectroscopy of the Amide I band of proteins is a powerful method for the determination of protein conformations and further allows the analysis of continuously flowing solutions of the target molecule.

Abstract: Selenium exists in different oxidation states (+6, +4, ±0, -2) in diverse environmental compartments. Different properties are related to these oxidation states, for example water solubility, which is closely correlated with the migration capability and the bioavailability.
In this study, the availability of inorganic selenium species was investigated in different laboratory experiments to get information on the mobility of these species. Hereby selenite adsorbed on goethite was incubated with a pure culture of active methylating fungus Alternaria alternata as well as with an enriched environmental mixed culture.

Abstract: Deposition kinetics of β-lactoglobulin at a solid−liquid interface was studied with optical waveguide lightmode spectroscopy (OWLS) over a range of temperatures between 61 and 83 °C. A new temperature-controlled cell for OWLS measurements allows fast, on-line monitoring of the deposit formation at elevated temperatures. Primary protein layers were deposited at 25 °C in order to precondition and stabilize the waveguide surface. Sustained deposition lasting from a few minutes (around 80 °C) to hours (below 70 °C) resulted in multilayer deposits up to several tens of nanometers thick. The measured deposition rates were strongly influenced by temperature, pH, and NaCl concentration. 

Abstract: Deposition of dissolved or suspended material from liquids at solid surfaces is present in various applications occurring not only in chemical process technologies, but also in many food, biomedical, environmental and mineral processing industries. Control of deposition phenomena through appropriate design of surface properties has been subject of much interest in recent years. Read more