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...

The mixed disulfide derivative of fully reduced neochymotrypsinogen was refolded at pH 9.2 and 4 degrees C with 4 mM cysteine as the disulfide interchange catalyst. The yield of regenerated neochymotrypsinogen was 25%; the corresponding yield of refolded chymotrypsinogen was 50%. The refolded neochymotrypsinogen exhibited the characteristics of the native molecule as determined from polyacrylam...

Since immobilized metal ion affinity chromatography (IMAC) was first introduced, several variants of this method and many other metal affinity-based techniques have been devised. IMAC quickly established itself as a highly reliable purification procedure, showing rapid expansion in the number of preparative and analytical applications while not remaining confined to protein separation. It was s...

The ellipticities for an early transient intermediate in refolding observed by kinetic circular dichroism measurements at 220-225 nm for 14 different proteins are summarized, and the ellipticity values are compared with those for the final native proteins and also with the ellipticities expected from a physical theory of protein and polypeptide secondary structure. The results show that a subst...

Cross-linked triclinic lysozyme was denatured with sodium dodecyl sulfate. Removal of the denaturant resulted in a refolding of the protein to a conformation similar to but not identical with the native one. Three-dimensional x-ray diffraction data out to 3.2-A resolution were collected for two states in the refolding pathway, and appropriately weighted electron density difference maps were con...

The stability of OmpA in large unilamellar vesicles of dilauroyl phosphatidylcholine was studied using different concentrations of urea. The effective energy of unfolding, as determined from refolding experiments, is greater than that for small sonicated unilamellar vesicles by an amount that is compatible with estimates of the elastic energy of highly curved vesicles. The on-rate for refolding...

Inclusion body refolding processes are poised to play a major role in the production of recombinant proteins. Improving renaturation yields by minimizing aggregation and reducing chemical costs are key to the industrial implementation of these processes. Recent developments include solubilization methods that do not rely on high denaturant concentrations and the use of high hydrostatic pressure...

The FK506 (tacrolimus)-binding protein (FKBP) type peptidyl-prolyl cis-trans isomerase (PPIase) in the hyperthermophilic archaeum Thermococcus sp. KS-1 was shown to be induced by temperature downshift to growth temperatures lower than the optimum. This PPIase (TcFKBP18) showed chaperone-like protein refolding activity in addition to PPIase activity in vitro. It refolded unfolded citrate synthas...

Mechanical unfolding and refolding of single RNA molecules have previously been observed in optical traps as sudden changes in molecular extension. Two methods have been traditionally used: "force-ramp", with the applied force continuously changing, and "hopping". In hopping experiments the force is held constant and the molecule jumps spontaneously between two different states. Unfolding/refol...