Rabbit muscle phosphofructokinase is rapidly inactivated at pH 8.0 by incubation with low concentrations of oxidized glutathione, Coenzyme A glutathione mixed disulfide, and oxidized Coenzyme A. The inactivation is first order in disulfide concentration over the concentration ranges examined (50-200 microM), and is approximately 8-fold slower at pH 7.0 than at pH 8.0. The substrates ATP and fru...

The gammaA2-subgroup of gammaA-globulins, previously delineated by antigenic studies, was found to differ strikingly from other immunoglobulins in the manner in which the polypeptide chains are bound together. The heavy and light chains were not linked to each other by disulfide bonds. Instead the light chains were disulfide linked to one another, and were present in the gammaA2-molecule as dis...

Protein-disulfide isomerase (PDI) is an abundant protein of the endoplasmic reticulum that catalyzes dithiol oxidation and disulfide bond reduction and isomerization using the active site CGHC. Haploid pdi1 delta Saccharomyces cerevisiae are inviable, but can be complemented with either a wild-type rat PDI gene or a mutant gene coding for CGHS PDI (shufflease). In contrast, pdi1 delta yeast can...

In some natural collagen triple helices, cysteine (Cys) residues on neighboring strands are linked by disulfide bonds, enhancing association and maintaining proper register. Similarly, Cys-Cys disulfide bridges have been used to impose specific associations between collagen-mimetic peptides (CMPs). Screening a library of disulfide linkers in silico for compatibility with collagen identifies the...

Determining the mechanism by which proteins attain their native structure is an important but difficult problem in basic biology. The study of protein folding is difficult because it involves the identification and characterization of folding intermediates that are only very transiently present. Disulfide bond formation is thermodynamically linked to protein folding. The availability of thiol t...

The endoplasmic reticulum (ER)-localized peroxiredoxin 4 (PRDX4) supports disulfide bond formation in eukaryotic cells lacking endoplasmic reticulum oxidase 1 (ERO1). The source of peroxide that fuels PRDX4-mediated disulfide bond formation has remained a mystery, because ERO1 is believed to be a major producer of hydrogen peroxide (H2O2) in the ER lumen. We report on a simple kinetic technique...

A fully functional cysteine-free derivative of the intrinsically stable anti-HER2 scFv fragment hu4D5-8 was generated by replacing the disulfide forming cysteine residues in VH and VL with the amino acid combination valine-alanine in both domains. The antigen binding properties, determined by ELISA and BIAcore measurements, were not affected by removal of the disulfide bonds. The thermodynamic ...

Torpedo acetylcholinesterase is a disulfide-linked homodimer containing three intramolecular disulfide bonds, as well as a single free thiol on Cys-231. We report that in a "molten globule" state, produced by 1.5 M guanidine hydrochloride, this enzyme undergoes rapid intramolecular thiol-disulfide exchange, in the absence of reducing agents, resulting in the production of novel species. Most st...

In this communication, we report on a new route to the functionalization of ATRP polymers exploiting their halide end-groups, which were converted successfully into reactive disulfide end-groups, using sodium methanethiosulfonate. The resultant disulfide-terminated polymers could then be reacted with different functional thiols to yield functional polymers exploiting either thiol/disulfide exch...