Proteinaceous nanomaterials and, in particular, virus-like particles (VLPs) have emerged as robust and uniform platforms that are seeing wider use in biomedical research. However, there are a limited number of bioconjugation reactions for functionalizing the capsids, and very few of those involve functionalization across the supramolecular quaternary structure of protein assemblies. In this wor...

A specific and sensitive assay for disulfide groups has been developed, based on reduction with dithioerythritol or dithiothreitol and determination of the resulting monothiols with 5,5’-dithiobis(2-nitrobenzoic acid) in the presence of arsenite. The dissociation constants for the complexes formed between arsenite and dithioeqthritol, dithiothreitol, 1,3-dithioglycerol, and 1,2-dithioglycerol h...

Ascorbic Acid, D isulfides, Redox-Potential, ESR Electron spin resonance (EPR) spectra dem onstrate the form ation of a com plex betw een the ascorbate ion and disulfides such as oxidized g lutathione, cystine, gam m a globulin, bovine serum album in, 4-4 ' d ith iopyrid ine, and dithiobutyric acid. However, except in the case o f 4-4 ' dithiopyridine, ascorbic acid (AH2) is not capable o f red...

We predicted that a significant source of background labeling after in situ hybridization (ISH) using 35 S-labeled probes is attributable to a chemical reaction between the phosphorothioate moiety of the probe [O 3 P 5 S] and disulfides in tissue. These covalent bonds would immobilize probe in the tissue, thereby increasing background labeling. On the basis of this view, we have explored the us...

A four-membered oxygen ring (oxetane) can be readily grafted into native peptides and proteins through site-selective bis-alkylation of cysteine residues present as disulfides under mild and biocompatible conditions. The selective installation of the oxetane graft enhances stability and activity, as demonstrated for a range of biologically relevant cyclic peptides, including somatostatin, prote...

PDI catalyzes the oxidative folding of disulfide-containing proteins. However, the sequence of reactions leading to a natively folded and oxidized protein remains unknown. Here we demonstrate a technique that enables independent measurements of disulfide formation and protein folding. We find that non-native disulfides are formed early in the folding pathway and can trigger misfolding. In contr...

A versatile synthetic strategy has been developed which enables the facile incorporation of cleavable functional groups, i.e., esters, thioesters, and disulfides, into the carbon-carbon backbone of vinyl-based polymers. Through the synthesis of novel cyclic monomers, RAFT-mediated radical ring-opening copolymerizations with traditional vinyl monomers such as methyl methacrylate, N,N-dimethylami...

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 ...

The presence of lipopolysaccharide (LPS) on the cell surface of Gram-negative bacteria is critical for viability. A conserved β-barrel membrane protein LptD (lipopolysaccharide transport protein D) translocates LPS from the periplasm across the outer membrane (OM). In Escherichia coli, this protein contains two disulfide bonds and forms the OM LPS translocon with the lipoprotein LptE. Here, we ...

The photoreactivity of l,3-dihydro-2H-benzim idazole-2-thione ( la ) and 2(3H )-benzothiazolethione ( lb ) has been studied in several solvents in the presence of oxygen with or without methylene blue as a sensitizer. The corresponding disulfides (5a , b), 2-oxo derivatives (2a , b), benzimidazole and benzothiazole (11a, b), and elem ental sulfur have been characterized as the main products. Th...