molecular dynamic simulation is a powerful method that monitors all variations in the atomic level in explicit solvent. by this method we can calculate many chemical and biochemical properties of large scale biological systems. in this work all-atom molecular dynamics simulation of polyalanine (pa) was investigated in the presence of 0.224, 0.448, 0.673, 0.897 and 1.122 m of guanidinium chlorid...

We have screened various alkyl- and arylguanidinium derivatives as possible competitors of Na+ or Rb+ for the cation sites on renal Na+,K(+)-ATPase. Alkyl-monoguanidinium or alkylbisguanidinium (BisG) compounds (chain lengths of C3 to C10) competitively inhibit the occlusion of Rb+ and Na+ with an order of affinities C10 greater than C8 greater than C6 greater than C4 greater than C3. BisG comp...

Degradation of proteins is important for the operating life of biocatalysts and the shelf life of protein pharmaceuticals. We have previously found that the deactivating effects of salts on proteins can be correlated to an indicator of ion hydration, the B-viscosity coefficient of the anion in solution. Here, we test the influence of cations on protein kinetic stability by observing deactivatio...

A basic protein has been isolated from pig brain. The purification procedure consisted of repeated extractions with chloroform-methanol (2: 1 v/v), 10% sodium chloride, and dilute hydrochloric acid. The pH 2.4 to 2.6 fraction obtained from the repeated acid extraction was further purified by pH and (NH&SO4 fractionation, Sephadex G-100 gel filtration, and chromatography on Amberlite IRC-50 with...

Hen egg white riboflavin-binding protein (RfBP) contains nine disulphide bonds. Provided these remain intact, the refolding of RfBP after incubation in 6 M guanidinium chloride is highly efficient with at least 95% of the binding activity regained within 3 min. Kinetic studies indicate that this regain consists of at least two phases. When the disulphide bonds of RfBP are reduced, reoxidation u...