The intact three dimensional structure of proteins is essential for their biological function. Important to the stability of the tertiary structure are intra-molecular disulfide bonds. The structure of proteins is dynamic and important biological processes like protein-protein interactions or enzyme-substrate binding can lead to a change in the tertiary structure, which may result in the cleava...

Blankenship, L. C. (Eastern Utilization Research and Development Division, Washington D.C.), and M. J. Pallansch. Differential analysis of sulfhydryl and disulfide groups of intact spores. J. Bacteriol. 92:1615-1617. 1966.-Fluorescence quenching of fluorescein mercuric acetate in alkaline medium (1 n NaOH) was found to be an accurate, sensitive method for differential analysis of sulfhydryl and...

The thioredoxin fold is the core scaffold of numerous proteins that control disulfide redox activity in the cell (1–3). These redox proteins share very little sequence homology, but all of them incorporate the four-stranded -sheet, three flanking -helices, and the redox-active CXXC motif of the TRX5 fold (Fig. 1A). The archetype of the family is thioredoxin (4), a disulfide reductase thatmainta...

UNLABELLED We investigated whether there is any association between a native-like conformation and the presence of only the canonical (i.e., native) disulfide bonds in the gp120 subunits of a soluble recombinant human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoprotein. We used a mass spectrometry (MS)-based method to map the disulfide bonds present in nonnative uncleaved gp140 pr...

Human defensins play multiple roles in innate immunity including direct antimicrobial killing and immunomodulatory activity. They have three disulfide bridges which contribute to the stability of three anti-parallel β-strands. The exact role of disulfide bridges and canonical β-structure in the antimicrobial action is not yet fully understood. In this study, we have explored the antimicrobial a...

The articles in this forum issue describe various aspects of the folding of disulfide-rich proteins. They include review articles using proteins such as bovine pancreatic trypsin inhibitor as models to highlight the range of folding pathways seen in disulfide-rich proteins, along with a detailed analysis of the methods used to study them. Following two comprehensive reviews on the methods and a...

Four different disulfide bridges (linking positions 9-164, 21-142, 90-122, and 127-154) were introduced into a cysteine-free phage T4 lysozyme at sites suggested by theoretical calculations and computer modeling. The new cysteines spontaneously formed disulfide bonds on exposure to air in vitro. In all cases the oxidized (crosslinked) lysozyme was more stable than the corresponding reduced (non...

Alkaline phosphatase of Escherichia coli (a homodimeric protein found in the periplasmic space) contains two intramolecular disulfide bonds (Cys-168-Cys-178 and Cys-286-Cys-336) that are formed after export to the periplasmic space. The location-specific folding character of this enzyme allowed its wide usage as a reporter of protein localization in prokaryotic cells. To study the roles of disu...