Using recombinant variants of BPTI, we have determined the rate constants corresponding to formation of each of the fifteen possible disulfide bonds in BPTI, starting from the reduced, unfolded protein. The 14-38 disulfide forms faster than any of the other 14 possible disulfides. This faster rate results from significantly higher intrinsic chemical reactivities of Cys-14 and Cys-38, in additio...

The majority of protein disulfides in cells is considered an important inert structural, rather than a dynamic regulatory, determinant of protein function. Here, we show that some disulfides in proteins also are regulated by cell redox status with functional consequences. We find that reactive oxygen species (ROS) produced by mitochondria are actively used by cells to facilitate cell-surface pr...

BACKGROUND Disulfide bonds are one of the most common post-translational modifications found in proteins. The production of proteins that contain native disulfide bonds is challenging, especially on a large scale. Either the protein needs to be targeted to the endoplasmic reticulum in eukaryotes or to the prokaryotic periplasm. These compartments that are specialised for disulfide bond formatio...

Potato carboxypeptidase inhibitor (PCI) contains 39 amino acids and three disulfides. Reduced and denatured PCI refolds spontaneously in vitro to regain its native structure. The folding pathway of a recombinant form of this protein has been elucidated by structural analysis and stop/go folding experiments of both acid and iodoacetate-trapped intermediates. The results reveal that folding of PC...

Abstract Molybdenum disulfide (MoS 2 ) is an effective friction modifier that can be formed on surfaces from oil-soluble lubricant additives. Different additive chemistries used to form MoS a surface. The tribofilms three different molybdenum additives (MoDTC Dimer, MoDTC Trimer, and molybdate ester) were studied in monoblends fully formulated systems. resulting then characterized by Raman spec...

The developing endosperm of rice (Oryza sativa, Os) synthesizes a large amount of storage proteins on the rough (r)ER. The major storage proteins, glutelins and prolamins, contain either intra or intermolecular disulfide bonds, and oxidative protein folding is necessary for the sorting of the proteins to the protein bodies. Here, we investigated an electron transfer pathway for the formation of...

The study of thrombus formation has increasingly applied in vivo tools such as genetically modified mice and intravital microscopy to the evaluation of molecular and cellular mechanisms of thrombosis. Among several unexpected findings of this approach was the discovery that protein disulfide isomerase serves an essential role in thrombus formation at sites of vascular injury. The observation th...

The mechanism by which mechanical force regulates the kinetics of a chemical reaction is unknown. Here, we use single-molecule force-clamp spectroscopy and protein engineering to study the effect of force on the kinetics of thiol/disulfide exchange. Reduction of disulfide bonds through the thiol/disulfide exchange chemical reaction is crucial in regulating protein function and is known to occur...

To investigate the highly denatured state of ovalbumin (molecular mass of 42.7 kDa, four cysteine sulfhydryls and one cystine disulfide) using the disulfide rearrangement approach, we established the peptide-mapping procedure using a cysteine-labeling technique with a fluorescent dye that allows the quantitative analyses for the disulfide-involved half-cystines. Ovalbumin denatured at a low pro...

CD4 is a coreceptor for binding of T cells to APC and the primary receptor for HIV. The disulfide bond in the second extracellular domain (D2) of CD4 is reduced on the cell surface, which leads to formation of disulfide-linked homodimers. A large conformational change must take place in D2 to allow for formation of the disulfide-linked dimer. Domain swapping of D2 is the most likely candidate f...