The associative behaviour of bovine liver glutamate dehydrogenase has been studied by gel chromatography at neutral pH in 1 M guanidinium chloride and 1 M sodium chloride. In guanidinium chloride both the elution volume and the elution profile of the enzyme are independent of protein concentration, whereas in sodium chloride they are strongly dependent on it. In NaCl the enzyme behaves as expec...

More than 30 years ago, Nozaki and Tanford reported that the pK values for several amino acids and simple substances in 6 M guanidinium chloride differed little from the corresponding values in low salt (Nozaki, Y., and C. Tanford. 1967. J. Am. Chem. Soc. 89:736-742). This puzzling and counter-intuitive result hinders attempts to understand and predict the proton uptake/release behavior of prot...

a simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4h-benzo[b]pyrans scaffolds installing a three-component tandem knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. various aromatic aldehydes were util...

The methods of Hascall & Sajdera (1969) were used to compare the proteoglycans of human intervertebral disc with those of bovine nasal cartilage. In contrast with cartilage, most of the hexuronate of disc could be extracted at low shear with water or dilute salt solutions. Extracts of disc with 4M-guanidinium chloride were centrifugated in 0.4M-guanidinium chloride in a CsCl gradient. Analytica...

A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

Proteinpolysaccharide complex from bovine nasal cartilage exhibits a bimodal distribution of sedimentation coefficients when analyzed in the ultracentrifuge in associative solvents such as 0.5 M guanidinium chloride. The faster sedimenting mode disaggregates in dissociative solvents such as 4 M guanidinium chloride, giving a unimodal centrifugal pattern. Proteinpolysaccharide complex is separat...

The synthesis of a new class lawsone enaminone derivatives by using lawsone, triethyl orthoformate and aromatic amines in the presence guanidinium chloride under solvent-free conditions has been developed.

The reversible folding and unfolding of barley chymotrypsin inhibitor 2 (CI2) appears to be a rare example in which both equilibria and kinetics are described by a two-state model. Equilibrium denaturation by guanidinium chloride and heat is completely reversible, and the data can be fitted to a simple two-state model involving only native and denatured forms. The free energy of folding in the ...

The macromolecular properties of cervical-mucus glycoproteins (mucins) were studied as a function of the concentration of guanidinium chloride with conventional light-scattering, photon-correlation spectroscopy and sedimentation-velocity centrifugation. No evidence for an association of the mucins in 0.2M-NaCl as compared with 6M-guanidinium chloride was found at mucin concentrations below appr...