An effective free energy potential, developed originally for binding free energy calculation, is compared to calorimetric data on protein unfolding, described by a linear combination of changes in polar and nonpolar surface areas. The potential consists of a molecular mechanics energy term calculated for a reference medium (vapor or nonpolar liquid), and empirical terms representing solvation a...

Coordinate analysis of the multiple phase transitions in hexagonal YMnO(3) leads to the prediction of a previously unknown aristotype phase, with the resulting phase-transition sequence: P6(3)'cm'(e.g.) <--> P6(3)cm <--> P6(3)/mcm <--> P6(3)/mmc <--> P6/mmm. Below the Néel temperature T(N) approximately = 75 K, the structure is antiferromagnetic with the magnetic symmetry not yet determined. Ab...

Aggregation of bacteriochlorophyll (BChl) c from chlorosomes, the main light-harvesting complex of green bacteria, has been studied in aqueous buffer. Unlike other chlorophyll-like molecules, BChl c is rather soluble in aqueous buffer, forming dimers. When BChl c is mixed with carotenoids (Car), the BChl c Qy transition is further redshifted, in respect to that of monomers and dimers. The resul...

The nature of the amino acids in the N-terminal 'DAGX' motif of the coat protein of tobacco vein mottling virus (TVMV) that have a direct effect on aphid transmissibility of the virion were further defined by site-directed mutagenesis. In the first position of the DAGX motif, Asp or Asn are required for aphid transmissibility. In the second position, the nonpolar residue Ala, but not the nonpol...

The photophysical properties of o-aminoacetophenone (o-AAP) in solution have been studied by using a femtosecond laserÈsingle photon counting system and time-resolved thermal lensing (TRTL) method. The Ñuorescence quantum yield and lifetime of o-AAP depend strongly on the nature of the solvent. In f (qf) nonpolar solvents, o-AAP gives very small values in n-hexane) and remarkably short f (Uf\ 2...

Zeta potentials of several polar protic (water, ethylene glycol, and formamide) as well as polar aprotic (dimethyl sulfoxide) liquids were measured in contact with three nonpolar surfaces using closed-cell electroosmosis. The test surfaces were chemisorbed monolayers of alkyl siloxanes, fluoroalkyl siloxanes, and polydimethylsiloxanes (PDMS) grafted on glass slides. All these liquids exhibited ...

Combinatorial libraries of well-folded de novo proteins can provide a rich source of reagents for the isolation of novel molecules for biotechnology and medicine. To produce libraries containing an abundance of well-folded sequences, we have developed a method that incorporates both rational design and combinatorial diversity. Our method specifies the "binary patterning" of polar and nonpolar a...

We investigate driving forces of the liquid-liquid phase separation of N-isopropylpropionamide (NiPPA) aqueous solutions above the lower critical solution temperature using molecular dynamics simulations. Spontaneous phase separations of the model aqueous solution with a modified OPLS-AA force field are observed above the experimentally determined cloud point. The destabilization toward the pha...

Gynostemma pentaphyllum (Thunb.) Makino (GpM) has been widely used in traditional Chinese medicine (TCM) for the treatment of various diseases including cancer. Most previous studies have focused primarily on polar fractions of GpM for anticancer activities. In this study, a nonpolar fraction EA1.3A from GpM showed potent growth inhibitory activities against four cancer cell lines with IC50 ran...

The multiphonon emission capture mechanism by neutral centers, in the presence of an electric field below 1 MV/cm, has been numerically simulated by the Monte Carlo method. Based on common models for the initial and final states, a simple expression of the process probability has been calculated considering both nonpolar and polar electron-phonon coupling. The validity range of this expression ...