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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Chemistry

Selected Works

Adam R Urbach

2015

Solutions

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Charge-Mediated Recognition Of N-Terminal Tryptophan In Aqueous Solution By A Synthetic Host, Meghan Bush, Nicole Bouley, Adam Urbach Nov 2015

Charge-Mediated Recognition Of N-Terminal Tryptophan In Aqueous Solution By A Synthetic Host, Meghan Bush, Nicole Bouley, Adam Urbach

Adam R Urbach

The molecular recognition of peptides and proteins in aqueous solution by designed molecules remains an elusive goal with broad implications for basic biochemical research and for sensors and separations technologies. This paper describes the recognition of N-terminal tryptophan in aqueous solution by the synthetic host cucurbit[8]uril (Q8). Q8 is known to form 1:1:1 heteroternary complexes with methyl viologen (MV) and a second aromatic guest. Here, the complexes of Q8·MV with (i) the four natural aromatic α-amino acids, (ii) four singly charged tryptophan derivatives, and (iii) four tryptophan-containing tripeptides were characterized by isothermal titration calorimetry, mass spectrometry, and UV−visible, fluorescence, and …


Sequence-Specific Recognition And Cooperative Dimerization Of N-Terminal Aromatic Peptides In Aqueous Solution By A Synthetic Host, Lisa Heitmann, Alexander Taylor, P Hart, Adam Urbach Nov 2015

Sequence-Specific Recognition And Cooperative Dimerization Of N-Terminal Aromatic Peptides In Aqueous Solution By A Synthetic Host, Lisa Heitmann, Alexander Taylor, P Hart, Adam Urbach

Adam R Urbach

This article describes the selective recognition and noncovalent dimerization of N-terminal aromatic peptides in aqueous solution by the synthetic host compound, cucurbit[8]uril (Q8). Q8 is known to bind two aromatic guests simultaneously and, in the presence of methyl viologen, to recognize N-terminal tryptophan over internal and C-terminal sequence isomers. Here, the binding of Q8 to aromatic peptides in the absence of methyl viologen was studied by isothermal titration calorimetry (ITC), 1H NMR spectroscopy, and X-ray crystallography. The peptides studied were of sequence X-Gly-Gly, Gly-X-Gly, and Gly-Gly-X (X = Trp, Phe, Tyr, and His). Q8 selectively binds and dimerizes Trp-Gly-Gly …