Topologically homologous four-helix-bundle heme proteins exhibit striking diversity in their refolding kinetics. Cytochrome b562 has been reported to fold on a sub-millisecond time scale, whereas cytochrome c' refolding requires 10 s or more to complete. Heme dissociation in cytochrome b562 interferes with studies of folding kinetics, so a variant of cytochrome b562 (cytochrome c-b562) with a c...

Mechanical folding trajectories for polyproteins starting from initially stretched conformations generated by single-molecule atomic force microscopy experiments [Fernandez, J. M. & Li, H. (2004) Science 303, 1674-1678] show that refolding, monitored by the end-to-end distance, occurs in distinct multiple stages. To clarify the molecular nature of folding starting from stretched conformations, ...

Protein folding is subject to the effects of solvation environment. A variety of organic solvents are used as additives for in vitro refolding of denatured proteins. Examination of the solvent effects on protein folding could be of fundamental importance to understand the molecular interactions in determining protein structure. This article investigated the folding of α-helix and β-hairpin stru...

Anionic tobacco peroxidase (TOP) is extremely active in chemiluminescence reaction of luminol oxidation without addition of enhancers and more stable than horseradish peroxidase under antibody conjugation conditions. In addition, recombinant TOP (rTOP) produced in Escherichia coli is known to be a perfect direct electron transfer catalyst on electrodes of various origin. These features make the...

The refolding of guanidine hydrochloride-denatured horse heart ferricytochrome c at pH 7.0 and 23 degrees C occurs in three kinetic phases as observed by stopped flow measurements using changes in Soret absorbance or in tryptophan fluorescence. The three kinetic phases have time constants of 10 +/- 5 ms, 240 +/- 30 ms, and 13 +/- 3 s accounting for 15 +/- 5%, 70 +/- 5%, and 15 +/- 5% of the tot...

Influenza virus infections represent an ongoing public health threat as well economic burden. Although seasonal influenza vaccines have been available for some decades, efforts are being made to generate new efficient, flexible, and cost-effective technologies be transferred into production. Our work describes the development of a model hemagglutinin antigen that is capable inducing protection ...

background: recombinant proteins overexpressed in e. coli are usually deposited in inclusion bodies. cysteines in the protein contribute to this process. inter- and intra- molecular disulfide bonds in chitinase, a cysteine-rich protein, cause aggregation when the recombinant protein is overexpressed in e. coli. hence, aggregated proteins should be solubilized and allowed to refold to obtain nat...

Effects of ?-cyclodextrin, ?CD, on refolding of lysozyme was investigated at pH 12 employing isothermal titration calorimetry (ITC) at 300K in 30mM Tris buffer solution. ?CD was employed as an anti-aggregation agent and the heats obtained for lysozyme+?CD interactions are reported and analyzed in terms of the extended solvation model. It was indicated that there are two sets of identical and no...