The Binding of Drug Molecules to Serum Albumin: The Effect of Drug Hydrophobicity on Binding Strength and Protein Desolvation.

In this work, dual polarization interferometry (DPI) and quartz crystal microgravimetry with dissipation monitoring (QCM-D) were used to examine the binding characteristics and structure-activity relationships of 12 common drugs on a model bovine serum albumin (BSA) film. By taking advantage of the different hydration sensitivities of DPI and QCM-D, we were able to quantify changes in the solvent state upon drug binding to BSA. Quantifying the changes in water mass within binding pockets and upon drug-protein binding allows for a more complete understanding of binding phenomena between drug molecules and serum proteins. For the drugs tested, a quantitative structure-activity relationship (QSAR) was used to establish a correlation between drug binding (KD) and hydrophobicity (ClogP), with the latter being related to the drug's ability to desolvate the BSA upon binding. Understanding these relationships provides insight into the role of water at the protein-ligand interface and is of particular importance in the area of ligand binding within the field of drug design. This study underscores the importance of hydrophobicity to drug binding kinetics and may be used to further understand and improve drug design and delivery protocols.

Switchable photovoltaic windows enabled by reversible photothermal complex dissociation from methylammonium lead iodide.

Materials with switchable absorption properties have been widely used for smart window applications to reduce energy consumption and enhance occupant comfort in buildings. In this work, we combine the benefits of smart windows with energy conversion by producing a photovoltaic device with a switchable absorber layer that dynamically responds to sunlight. Upon illumination, photothermal heating switches the absorber layer-composed of a metal halide perovskite-methylamine complex-from a transparent state (68% visible transmittance) to an absorbing, photovoltaic colored state (less than 3% visible transmittance) due to dissociation of methylamine. After cooling, the methylamine complex is re-formed, returning the absorber layer to the transparent state in which the device acts as a window to visible light. The thermodynamics of switching and performance of the device are described. This work validates a photovoltaic window technology that circumvents the fundamental tradeoff between efficient solar conversion and high visible light transmittance that limits conventional semitransparent PV window designs.