Hydrolysis of chemically distinct sites of human serum albumin by polyoxometalate: A hybrid QM/MM (ONIOM) study

In this study, mechanisms of hydrolysis of all four chemically diverse cleavage sites of human serum albumin (HSA) by [Zr(OH)(PW₁₁O₃₉)]⁴⁻ (ZrK) have been investigated using the hybrid two-layer QM/MM (ONIOM) method. These reactions have been proposed to occur through the following two mechanisms: internal attack (IA) and water assisted (WA). In both mechanisms, the cleavage of the peptide bond in the Cys392-Glu393 site of HSA is predicted to occur in the rate-limiting step of the mechanism. With the barrier of 27.5 kcal/mol for the hydrolysis of this site, the IA mechanism is found to be energetically more favorable than the WA mechanism (barrier = 31.6 kcal/mol). The energetics for the IA mechanism are in line with the experimentally measured values for the cleavage of a wide range of dipeptides. These calculations also suggest an energetic preference (Cys392-Glu393, Ala257-Asp258, Lys313-Asp314, and Arg114-Leu115) for the hydrolysis of all four sites of HSA. © 2018 Wiley Periodicals, Inc.     

Investigations on the reversible heat generation rates of blended Li-insertion electrodes

Journal of Solid State Electrochemistry - Recently, considerable improvements regarding the electrochemical performance of cathodes for lithium-ion batteries have been achieved by combining...     

Magnetic Resonance Spectra and Statistical Geometry

Methods of statistical geometry are introduced which allow one to estimate, on the basis of computable criteria, the conditions under which maximally informative data may be collected. We note the important role of constraints which introduce curvature into parameter space and discuss the appropriate mathematical tools for treating curvature effects. Channel capacity, a term from communication theory, is suggested as a useful figure of merit for estimating the information content of spectra in the presence of noise. The tools introduced here are applied to the case of a model nitroxide system as a concrete example, but we stress that the methods described here are of general utility.     

Synthesis and Properties of a New Kind of One-Dimensional Conductors 17. Studies on monomeric and polymeric phthalocyaninato-iron(II) and -cobalt(II) complexes

A new approach for a one-dimensional organic conductor with a chemically bonded backbone is presented. The proposed compounds consist of a linear arrangement of transition metal atoms, e.g. Fe, Co, bridged by linear bidentate π-electron containing ligands, e.g. pyrazine, 4,4'-bipyridine, and 1,4-diisocyanobenzene. This structure is stabilized by the tetradentate planar phthalocyanine molecule complexing each octahedrally coordinated central atom in its equatorial plane. The synthesis and characterization of the monomeric, dimeric and polymeric compounds PcML/PcML₂, PcM-L-PcM and [PcML]_n are described and a comparison of their electrical conductivity as a function of their structural features is given in detail. The electrical conduction of the monomeric units increases after polymerisation by a factor of 10⁷ without doping. In the second part soluble tetrasubstituted phthalocyaninato(IVB)-metalloxanes are described and the effect of homogeneous and heterogeneous iodination on conductivity is discussed.