Abstract
Electrostatics affect virtually all aspects of protein structure and activity and are particularly important in proteins whose primary function is to stabilize charge. Here we introduce a fluorescent amino acid, Aladan, which can probe the electrostatic character of a protein at multiple sites. Aladan is exceptionally sensitive to the polarity of its surroundings and can be incorporated site-selectively at buried and exposed sites, in both soluble and membrane proteins. Steady-state and time-resolved fluorescence measurements of Aladan residues at different buried and exposed sites in the B1 domain of protein G suggest that its interior is polar and heterogeneous.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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2-Naphthylamine / analogs & derivatives
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2-Naphthylamine / chemical synthesis
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2-Naphthylamine / chemistry*
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Alanine / analogs & derivatives
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Alanine / chemical synthesis
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Alanine / chemistry*
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Amino Acid Sequence
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Amino Acid Substitution
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Amino Acids / chemical synthesis
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Amino Acids / chemistry*
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Anisotropy
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Bacterial Proteins / chemistry*
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Dimethyl Sulfoxide
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Fluorescence
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Molecular Sequence Data
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Nuclear Magnetic Resonance, Biomolecular
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Potassium Channels / chemistry
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Potassium Channels / physiology
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Potassium Channels, Inwardly Rectifying / chemistry
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Potassium Channels, Inwardly Rectifying / physiology
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Protein Folding
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Protein Structure, Tertiary
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Proteins / chemistry*
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Shaker Superfamily of Potassium Channels
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Solvents
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Spectrometry, Fluorescence
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Static Electricity
Substances
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Amino Acids
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Bacterial Proteins
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IgG Fc-binding protein, Streptococcus
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Potassium Channels
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Potassium Channels, Inwardly Rectifying
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Proteins
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Shaker Superfamily of Potassium Channels
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Solvents
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aladan
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2-Naphthylamine
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Alanine
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Dimethyl Sulfoxide