The electrochemistry of disulfides incorporated into the sugar-phosphate backbone of pyrene-modified DNA has been examined on highly oriented pyrolytic graphite (HOPG). Two signals, one irreversible, one reversible, are observed at -160 and -290 mV versus normal hydrogen electrode, respectively. The inclusion of a single base mismatch in the DNA duplex below the location of the disulfide leads ...

Animal toxins are the major class of secreted disulfide-rich proteins, with approximately 70% containing two or more disulfide bonds. Incorrect pairing of these disulfide bonds typically leads to a non-native three-dimensional fold accompanied by a loss of protein function. Determination of the native disulfide-bond framework is therefore a key component in the structural characterization of to...

We describe an efficient photoredox system, relying on decatungstate/disulfide catalysts, for the hydrofunctionalization of styrenes. In this methodology use disulfide as a cocatalyst was shown to be crucial reaction efficiency. This system employed hydro-carbamoylation, -acylation, -alkylation, and -silylation styrenes, giving access large variety useful building blocks high-value molecules su...

The number of total disulfide bonds in rabbit and sheep 7S gamma globulin, before and after treatment with 2-mercaptoethanol, has been measured by amperometric titration. Mercaptan reduction could diminish the complement-fixing efficiency of 7S rabbit gamma globulin by no more than 90 per cent without any significant decrease in maximal complement-fixing ability. This was associated with the re...

Native disulfide bond formation is essential for the folding of many proteins. The enzyme protein disulfide isomerase (POI) catalyzes native disulfide bond formation using a Cys-Gly-HisCys active site. The active-site properties of POI (thiol pK. = 6.7 and disulfide E;O' = -180 mY) are critical for efficient catalysis. This Dissertation describes the design, synthesis, and characterization of s...

The ER (endoplasmic reticulum) has long been considered the plant cell compartment within which protein disulfide bond formation occurs. Members of the ER-located PDI (protein disulfide isomerase) family are responsible for oxidizing, reducing and isomerizing disulfide bonds, as well as functioning as chaperones to newly synthesized proteins. In the present study we demonstrate that an abundant...

Irradiation of proteins with intense X-ray radiation produced by third-generation synchrotron sources generates specific structural and chemical alterations, including breakage of disulfide bonds and decarboxylation. In this paper, disulfide bond lengths in irradiated crystals of the enzyme Torpedo californica acetylcholinesterase are examined based on quantum simulations and on experimental da...

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...

In order to characterize possible disulfide-linked interactions between lens fiber cell membranes and crystallins, two-dimensional diagonal electrophoresis has been used in combination with Western blot analysis. When these blots were probed with monospecific antisera against alpha, beta and gamma crystallins, membrane from five individual normal lenses showed no disulfide-bonded components. Me...