Quantitative reactivity profiling predicts functional cysteines in proteomes.

The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
Nature (Impact Factor: 42.35). 11/2010; 468(7325):790-5. DOI: 10.1038/nature09472
Source: PubMed

ABSTRACT Cysteine is the most intrinsically nucleophilic amino acid in proteins, where its reactivity is tuned to perform diverse biochemical functions. The absence of a consensus sequence that defines functional cysteines in proteins has hindered their discovery and characterization. Here we describe a proteomics method to profile quantitatively the intrinsic reactivity of cysteine residues en masse directly in native biological systems. Hyper-reactivity was a rare feature among cysteines and it was found to specify a wide range of activities, including nucleophilic and reductive catalysis and sites of oxidative modification. Hyper-reactive cysteines were identified in several proteins of uncharacterized function, including a residue conserved across eukaryotic phylogeny that we show is required for yeast viability and is involved in iron-sulphur protein biogenesis. We also demonstrate that quantitative reactivity profiling can form the basis for screening and functional assignment of cysteines in computationally designed proteins, where it discriminated catalytically active from inactive cysteine hydrolase designs.

  • Synlett 09/2014; 25(16):2239-2245. · 2.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A very facile approach for the design and fabrication of a colorimetric sensor array, by using only a single indicator-receptor couple at various ratios and concentrations, is described for the first time. As a proof-of-concept application, discrimination and identification of the 20 natural amino acids has been successfully accomplished. Classification analyses demonstrate that the as-fabricated colorimetric sensor array has a high dimensionality and, consequently, has the capability to recognize the 20 natural amino acids. Moreover, the amino acids can be qualitatively and semi-quantitatively detected by combining classification analyses, recognition patterns and corresponding fitting curves. The strategy developed in the current study likely represents a “maximally” simplified approach for design and fabrication of colorimetric sensor arrays, and could be taken full advantage of among investigators in the sensing application field.
    RSC Advances 01/2014; 4(56):29581. · 3.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Biological thiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play important roles in maintaining the appropriate redox status of biological systems. The discrimination between them is of great importance because of their different biological roles. Herein, we present a new near-infrared (NIR) fluorescent sensor Cy-NO2 for selective detection of Cys over Hcy/GSH. The nitrothiophenol group is introduced to quench the fluorescence through photo-induced electron transfer (PET). The sensor undergoes displacement of nitrothiophenol with thiol to turn on the fluorescence. The amino groups of Cys/Hcy further replace the thiolate to form amino-substituted products, which exhibit dramatically different photophysical properties compared to the sulfur-substituted product from the reaction with GSH. By means of more rapid intramolecular displacement of sulfur with the amino group of Cys than Hcy, the discrimination of Cys is achieved. Moreover, Cy-NO2 was successfully applied for bioimaging Cys in living cells.
    RSC Advances 01/2014; 4(16):8360. · 3.71 Impact Factor

Full-text (2 Sources)

Available from
May 16, 2014