title: Monitoring structural transitions in IDPs by vibrational spectroscopy of cyanylated cysteine.
abstract: The fast intrinsic time scale of infrared absorption and the sensitivity of molecular vibrational frequencies to their environments can be applied with site-specificity by introducing the artificial amino acid β-thiocyanatoalanine, or cyanylated cysteine, into chosen sites within intrinsically disordered proteins. This amino acid can be inserted through native chemical ligation at single cysteines introduced via site-directed mutagenesis. The CN stretching band of cyanylated cysteine is sensitive to local changes in both structural content and solvent exposure. This dual sensitivity makes cyanylated cysteine an especially useful probe of binding-induced structural transitions in IDPs. The general strategy of creating single-site cysteine mutations and chemically modifying them to create the vibrational chromophore, as well as observation, processing and analysis of the CN stretching band, is presented.
authors: Department of Chemistry, Haverford College, Haverford, PA, USA.
authors: Hailiu
authors: H
authors: Yang
authors: Johnny
authors: J
authors: Habchi
authors: Sonia
authors: S
authors: Longhi
authors: Casey H
authors: CH
authors: Londergan
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000737:chemistry; D000465:Algorithms; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D003545:Cysteine / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D017550:Spectroscopy, Fourier Transform Infrared; D013194:Staining and Labeling; D013861:Thiocyanates / Q000737:chemistry
chemical_list: D011993:Recombinant Fusion Proteins; D013861:Thiocyanates; D003545:Cysteine; D000409:Alanine