The RNase molecule consists of a single chain, arranged in a compact, folded structure, cross-linked through 4 disulfide bridges (1). After hydrolysis to determine the amino acid composition of RNase, 8 half-cystine or cysteic acid residues have been identified (2,3) and the approximate location of these residues in the partial structural formula for oxidized RNase has been determined (4). More...

The availability of the amino acid sequence of egg white lysoeyme makes it possible to identify the pairing of the 8 half-cystine residues that give rise to the four disulfide bonds present in the native protein (1,2). In establishing the positions of the disulfide bonds in insulin (3, 4) and ribonuclease (5, 6) it was shown that disulfide interchange, which occurs under certain experimental co...

In the ER (endoplasmic reticulum) of human cells, disulfide bonds are predominantly generated by the two isoforms of Ero1 (ER oxidoreductin-1): Ero1α and Ero1β. The activity of Ero1α is tightly regulated through the formation of intramolecular disulfide bonds to help ensure balanced ER redox conditions. Ero1β is less tightly regulated, but the molecular details underlying control of activity ar...

A molecule of rabbit yG-globulin’ evidently consists of four polypeptide chains held together by interchain disulfide bonds and noncovalent interactions. Each molecule comprises a pair of similar or identical “light” chains having an approximate molecular weight of 20,000, and another pair of “heavy” chains of weight 50,000 to 55,000 (2-7). Each light chain is linked to a heavy chain and the tw...

Polymers are often susceptible to premature failure due various physical damages. Incorporation of reversible disulfide bonds with sufficient chain diffusion in polyurethane (PU) elastomers endows them good healable...

Disulfide bonds are undoubtedly of great importance in stabilizing the native conformations of many proteins. For studies of the covalent structure of proteins it is desirable, as a first step, to cleave the disulfide bonds (1). This has been carried out either by oxidation (l-3) or by reduction followed by alkylation of the sulfhydryl groups formed (4). Iodoacetic acid (or iodoacetamide) has b...

Synopsis In the ER (endoplasmic reticulum) of human cells, disulfide bonds are predominantly generated by the two isoforms of Ero1 (ER oxidoreductin-1): Ero1α and Ero1β. The activity of Ero1α is tightly regulated through the formation of intramolecular disulfide bonds to help ensure balanced ER redox conditions. Ero1β is less tightly regulated, but the molecular details underlying control of ac...

A novel electrochemical (EC) method for fast and efficient reduction of the disulfide bonds in proteins and peptides is presented. The method does not use any chemical agents and is purely instrumental. To demonstrate the performance of the EC reactor cell online with electrospray mass spectrometry, insulin and somatostatin were used as model compounds. Efficient reduction is achieved in contin...

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...

The cysteines of the Escherichia coli periplasmic enzyme alkaline phosphatase, which are involved in disulfide bonds in the native enzyme, were found to be fully reduced when the protein was retained in the cytoplasm. Under these circumstances the cysteines remained reduced for at least several minutes after the synthesis of the protein was completed. This contrasted with the normally exported ...