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Physical Sciences and Mathematics Commons

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

2015

Chemistry

Selected Works

Fluorescence

Articles 1 - 5 of 5

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, Nanomolar Peptide Binding Via Cucurbit[8]Uril-Induced Folding And Inclusion Of Neighboring Side Chains, Lauren C. Smith, David G. Leach, Brittney E. Blaylock, Omar A. Ali, Adam R. Urbach Nov 2015

Sequence-Specific, Nanomolar Peptide Binding Via Cucurbit[8]Uril-Induced Folding And Inclusion Of Neighboring Side Chains, Lauren C. Smith, David G. Leach, Brittney E. Blaylock, Omar A. Ali, Adam R. Urbach

Adam R Urbach

This paper describes the molecular recognition of the tripeptide Tyr-Leu-Ala by the synthetic receptor cucurbit[8]uril (Q8) in aqueous buffer with nanomolar affinity and exceptional specificity. This combination of characteristics, which also applies to antibodies, is desirable for applications in biochemistry and biotechnology but has eluded supramolecular chemists for decades. Building on prior knowledge that Q8 binds to peptides with N-terminal aromatic residues, a library screen of 105 peptides was designed to test the effects of residues adjacent to N-terminal Trp, Phe, or Tyr. The screen used tetramethylbenzobis(imidazolium) (MBBI) as a fluorescent indicator and resulted in the unexpected discovery that MBBI …


Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang Sep 2015

Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang

Yi Pang

Mitochondria, vital organelles existing in almost all eukaryotic cells, play a crucial role in energy metabolism and apoptosis of aerobic organisms. In this work, we report two new flavone-based fluorescent probes, MC-Mito1 and MC-Mito2, for monitoring mitochondria in living cells. These two probes exhibit remarkably low toxicity, good cell permeability, and high specificity; these probes complement the existing library of mitochondrial imaging agents. The new dyes give nearly no background fluorescence, and their application does not require tedious postwashing after cell staining. The appreciable tolerance of MC-Mito2 encourages a broader range of biological applications for understanding the cell degeneration and …


Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang Sep 2015

Biocompatible Flavone-Based Fluorogenic Probes For Quick Wash-Free Mitochondria! Imaging In Living Cells, Bin Liu, Mickey Shah, Ge Zhang, Qin Liu, Yi Pang

Ge Zhang

Mitochondria, vital organelles existing in almost all eukaryotic cells, play a crucial role in energy metabolism and apoptosis of aerobic organisms. In this work, we report two new flavone-based fluorescent probes, MC-Mito1 and MC-Mito2, for monitoring mitochondria in living cells. These two probes exhibit remarkably low toxicity, good cell permeability, and high specificity; these probes complement the existing library of mitochondrial imaging agents. The new dyes give nearly no background fluorescence, and their application does not require tedious postwashing after cell staining. The appreciable tolerance of MC-Mito2 encourages a broader range of biological applications for understanding the cell degeneration and …


Binding-Induced, Turn-On Fluorescence Of The Egfr/Erbb Kinase Inhibitor, Lapatinib, James N. Wilson Mar 2015

Binding-Induced, Turn-On Fluorescence Of The Egfr/Erbb Kinase Inhibitor, Lapatinib, James N. Wilson

James N Wilson

We report the photophysical properties, binding-induced turn-on emission, and fluorescence imaging of the cellular uptake and distribution of lapatinib, an EGFR/ERBB inhibitor. Lapatinib, a type II, i.e. inactive state, inhibitor that targets the ATP binding pocket of the EGFR family of receptor tyrosine kinases. DFT calculations predict that the 6-furanylquinazoline core of lapatinib should exhibit an excited state with charge transfer character and an S0 to S1 transition energy of 3.4 eV. Absorption confirms an optical tran- sition in the near UV to violet, while fluorescence spectroscopy shows that photoemission is highly sensi- tive to solvent polarity. The hydrophobicity of …