Insulin-like growth factor I (IGF-I or somatomedin C) is a serum polypeptide with three intramolecular disulfide bonds. In the course of synthesis by the recombinant DNA method, three disulfide bond isomers, all of which have Cys18-Cys61 with three combinations of two disulfide bonds formed by Cys6, Cys47, Cys48 and Cys52, were identified. Natural type, isomer II, was proved to have a Cys6-Cys4...

AIMS Posttranslational formation of disulfide bonds is essential for the folding of many secreted proteins. Formation of disulfide bonds in a protein with more than two cysteines is inherently fraught with error and can result in incorrect disulfide bond pairing and, consequently, misfolded protein. Protein disulfide bond isomerases, such as DsbC of Escherichia coli, can recognize mis-oxidized ...

the zinc(ii) complex [zn2(dmdtc)2(μ-dmdtc)2] has been synthesized directly from thiram ligand, containing a disulfide bond {dmdtc = n,n-dimethyldithiocarbamate; thiram = n,n-tetramethylthiuram disulfide}, and characterized by elemental analysis and spectroscopic methods. surprisingly thiram, undergoes a reductive disulfide bond scission upon reaction with zn2+ in methanolic media to give the [z...

Disulfide bonds play an important role in protein folding and stability. However, the cross-linking of sites within proteins by cysteine disulfides has significant distance and dihedral angle constraints. Here we report the genetic encoding of noncanonical amino acids containing long side-chain thiols that are readily incorporated into both bacterial and mammalian proteins in good yields and wi...

One of the factors responsible for tertiary structural stabilization in proteins is the presence of the hydrophobic core—a result of hydrophobic interactions within the protein body. In some proteins (especially extracellular ones) additional stabilization is provided by covalent bonds between selected Cys residues, commonly referred to as disulfide bonds. The mutual interplay of both factors a...

The chemistry of disulfide exchange in biological systems is well studied. However, very little information is available concerning the actual origin of disulfide bonds. Here we show that DsbB, a protein required for disulfide bond formation in vivo, uses the oxidizing power of quinones to generate disulfides de novo. This is a novel catalytic activity, which to our knowledge has not yet been d...

The inter- and intrasubunit disulfide bridges for the 11 S form of acetylcholinesterase isolated from Torpedo californica have been identified. Localized within the basal lamina of the synapse, the dimensionally asymmetric forms of acetylcholinesterase contain either two (13 S) or three (17 S) sets of catalytic subunits linked to collagenous and noncollagenous structural subunits. Limited prote...

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...

The structures of two species of potato carboxypeptidase inhibitor with nonnative disulfide bonds were determined by molecular dynamics simulations in explicit solvent using disulfide bond constraints that have been shown to work for the native species. Ten structures were determined; five for scrambled A (disulfide bonds between Cys8-Cys27, Cys12-Cys18, and Cys24-Cys34) and five for the scramb...

Disulfide bonds between the side chains of cysteine residues are the only common crosslinks in proteins. Bovine pancreatic ribonuclease A (RNase A) is a 124-residue enzyme that contains four interweaving disulfide bonds (Cys26-Cys84, Cys40-Cys95, Cys58-CysllO, and Cys65-Cys72) and catalyzes the cleavage of RNA. The contribution of each disulfide bond to the confonnational stability and catalyti...