The apparent specific volume and adiabatic compressibility of lysozyme largely decreased upon guanidine hydrochloride denaturation. These results demonstrate that a large amount of amino acid residues exposes accompanying an increase in hydration and a decrease in the internal cavity. Both parameters deviated from the two-state transition curves, suggesting noncooperative disruption of the compactness and the secondary structure.
Photosensitized luminescence of Nd3+ in solution was successfully observed for the first time by coordinating the metal cation with deuterated 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-pentadecafluoro-1-pentafluorophenyl-1,3-decanedione as a ligand with a low vibrational chromophore.
The origin of cis-effect in 1,2-difluoroethene has been identified by quantitative analysis of electron delocalization using natural bond orbital analysis at the HF/6-311++G(3df, 3pd) level. It was concluded that both the delocalization of halogen lone-pair electrons (LP effect) and the antiperiplanar effects (AP effect) between vicinal antiperiplanar bonds are most likely to be the major sources of cis-effect with the latter effect being the more predominant.
An elecron-transfer complex of a substituted manganese porphyrin with tetracyanoethylene was prepared. Crystal structure analysis revealed that there exists quasi-two dimensional interaction in the complex, which was shown to be a magnet with Tc of 6.0 K.
A mononuclear rhenium(V) complex having a BF3 moiety on one of the two oxo ligands, trans-[ReV(O)(OBF3)(1-MeIm)4](BF4)(1-MeIm = 1-methylimidazole), was isolated and characterized. Two one-electron redox waves were observed in 0.1 M (n-C4H9)4NPF6/CH3CN (M = mol dm−3).
Aniline derivatives were found to be trasformed to fluorescent compounds on treatment with horseradish peroxidase/H2O2. DNA was detectable with high resolution in the horseradish peroxidase-linked immunosobent fluorescence assay of the membrane-bound DNA using one of the aniline derivatives. A new method for a simultaneous detection of two different DNA sequences was also achieved.
On treatment of allyl-t-butyldiphenylsilane with t-BuOK and 18-Crown-6 in DMSO at room temperature, isomerization of the olefinic double bond and subsequent substitution of phenyl group with hydroxy group took place smoothly to afford alkenylsilanol derivatives in good yields.
The chelation controlled additions of a MeLi dimer to alkoxy carbonyl compounds occur through an open dimer cluster, in which only one lithium atom participates in the chelate formation and the other acts as an anchor of the methyl nucleophile to be delivered to the carbonyl group. Solvation of a lithium atom with a water molecule does not change much the structure of the transition state.
Rates of oxidative decarboxylation of pyruvate by thymine-thiazolium were found to be accelerated by Zn2+ in the presence of a melamine derivative bearing an α-bipyridine moiety in CHCl3-MeCN (9 : 1 v/v) under anaerobic conditions.
A remarkably stable antigen immobilization on gold thin layer deposited on a glass using aminoethanethiol and oxidized dextran hydrosulfate matrix is reported. The polymer was thus covalently bound onto the gold thin layer, and human serum albumin (HSA) as an antigen was covalently bound on the polymer matrix. The association and the dissociation of anti-HSA (aHSA) with the bound HSA were repeatedly observed by surface plasmon resonance (SPR) measurement. The SPR signal vs. concentration of aHSA has a good experimental agreement with the Langmuir adsorption isotherm equation of the aHSA binding with HSA.