The Experts below are selected from a list of 3120 Experts worldwide ranked by ideXlab platform

Thomas J Meade - One of the best experts on this subject based on the ideXlab platform.

  • calcium induced morphological transitions in peptide amphiphiles detected by 19f magnetic resonance imaging
    ACS Applied Materials & Interfaces, 2017
    Co-Authors: Adam T Preslar, Laura M Lilley, Zer Keen Chia, Shanrong Zhang, Kohei Sato, Samuel I Stupp, Thomas J Meade
    Abstract:

    Misregulation of extracellular Ca2+ can indicate bone-related pathologies. New, noninvasive tools are required to image Ca2+ fluxes and fluorine magnetic resonance imaging (19F-MRI) is uniquely suited to this challenge. Here, we present three, highly fluorinated peptide amphiphiles that self-assemble into nanoribbons in buffered saline and demonstrate these nanostructures can be programmed to change 19F-NMR Signal Intensity as a function of Ca2+ concentration. We determined these nanostructures show significant reduction in 19F-NMR Signal as nanoribbon width increases in response to Ca2+, corresponding to 19F-MR image Intensity reduction. Thus, these peptide amphiphiles can be used to quantitatively image biologically relevant Ca2+ concentrations.

  • Calcium-Induced Morphological Transitions in Peptide Amphiphiles Detected by 19F‑Magnetic Resonance Imaging
    2017
    Co-Authors: Adam T Preslar, Laura M Lilley, Zer Keen Chia, Shanrong Zhang, Kohei Sato, Samuel I Stupp, Thomas J Meade
    Abstract:

    Misregulation of extracellular Ca2+ can indicate bone-related pathologies. New, noninvasive tools are required to image Ca2+ fluxes and fluorine magnetic resonance imaging (19F-MRI) is uniquely suited to this challenge. Here, we present three, highly fluorinated peptide amphiphiles that self-assemble into nanoribbons in buffered saline and demonstrate these nanostructures can be programmed to change 19F-NMR Signal Intensity as a function of Ca2+ concentration. We determined these nanostructures show significant reduction in 19F-NMR Signal as nanoribbon width increases in response to Ca2+, corresponding to 19F-MR image Intensity reduction. Thus, these peptide amphiphiles can be used to quantitatively image biologically relevant Ca2+ concentrations

Chiaki Nishimura - One of the best experts on this subject based on the ideXlab platform.

  • distinct residual and disordered structures of alpha synuclein analyzed by amide proton exchange and NMR Signal Intensity
    Biochimica et Biophysica Acta, 2020
    Co-Authors: Rina Okuwaki, Iori Shinmura, Shiki Morita, Akimasa Matsugami, F Hayashi, Yuji Goto, Chiaki Nishimura
    Abstract:

    Abstract The residual solution structures of two alpha-synuclein mutants, A30P and A53T, observed in family members of patients with Parkinson's disease were compared with that of wild-type by NMR. The A53T substitution had been shown to accelerate fibril formation of alpha-synuclein, whereas the A30P mutation has the negative and positive effects on the formation of the fibril and spherical oligomer, respectively. The remaining structure was analyzed via amide-proton exchange and Signal Intensity measurements using NMR. Amide-proton exchange was used for both the calculation of kex values and ratio of kex at different temperatures. Effects of the A30P (N-terminal region) mutation were observed at the C-terminal region as a more flexible structure, suggesting that long-range interactions exist between the N- and C-terminal regions in alpha-synuclein. In addition, the N-terminal region adopted a more rigid structure in the A53T and A30P mutants than in the wild-type. It was concluded that the structural change caused by the mutations is related to the formation of a beta-hairpin at the initiation site of the N-terminal core structure. Furthermore, the Signal Intensity was used to estimate the rigidity of the structure. Higher Signal intensities were observed for A30P at the 112, 113, and 116 C-terminal residues, suggesting that this region adopts more flexible structure. The ratio of the intensities at different temperatures indicated more flexible or rigid structures in the N-terminal region of A30P than in that of wild-type. Thus, using different approaches and temperatures is a good method to analyze residual structure in intrinsically disordered proteins.

Adam T Preslar - One of the best experts on this subject based on the ideXlab platform.

  • calcium induced morphological transitions in peptide amphiphiles detected by 19f magnetic resonance imaging
    ACS Applied Materials & Interfaces, 2017
    Co-Authors: Adam T Preslar, Laura M Lilley, Zer Keen Chia, Shanrong Zhang, Kohei Sato, Samuel I Stupp, Thomas J Meade
    Abstract:

    Misregulation of extracellular Ca2+ can indicate bone-related pathologies. New, noninvasive tools are required to image Ca2+ fluxes and fluorine magnetic resonance imaging (19F-MRI) is uniquely suited to this challenge. Here, we present three, highly fluorinated peptide amphiphiles that self-assemble into nanoribbons in buffered saline and demonstrate these nanostructures can be programmed to change 19F-NMR Signal Intensity as a function of Ca2+ concentration. We determined these nanostructures show significant reduction in 19F-NMR Signal as nanoribbon width increases in response to Ca2+, corresponding to 19F-MR image Intensity reduction. Thus, these peptide amphiphiles can be used to quantitatively image biologically relevant Ca2+ concentrations.

  • Calcium-Induced Morphological Transitions in Peptide Amphiphiles Detected by 19F‑Magnetic Resonance Imaging
    2017
    Co-Authors: Adam T Preslar, Laura M Lilley, Zer Keen Chia, Shanrong Zhang, Kohei Sato, Samuel I Stupp, Thomas J Meade
    Abstract:

    Misregulation of extracellular Ca2+ can indicate bone-related pathologies. New, noninvasive tools are required to image Ca2+ fluxes and fluorine magnetic resonance imaging (19F-MRI) is uniquely suited to this challenge. Here, we present three, highly fluorinated peptide amphiphiles that self-assemble into nanoribbons in buffered saline and demonstrate these nanostructures can be programmed to change 19F-NMR Signal Intensity as a function of Ca2+ concentration. We determined these nanostructures show significant reduction in 19F-NMR Signal as nanoribbon width increases in response to Ca2+, corresponding to 19F-MR image Intensity reduction. Thus, these peptide amphiphiles can be used to quantitatively image biologically relevant Ca2+ concentrations

Alexander B. Barnes - One of the best experts on this subject based on the ideXlab platform.

  • pulsed electron decoupling and strategies for time domain dynamic nuclear polarization with magic angle spinning
    Journal of Physical Chemistry Letters, 2018
    Co-Authors: Edward P. Saliba, Erika L. Sesti, Nicholas Alaniva, Alexander B. Barnes
    Abstract:

    Magic angle spinning (MAS) dynamic nuclear polarization (DNP) is widely used to increase nuclear magnetic resonance (NMR) Signal Intensity. Frequency-chirped microwaves yield superior control of electron spins and are expected to play a central role in the development of DNP MAS experiments. Time domain electron control with MAS has considerable promise to improve DNP performance at higher fields and temperatures. We have recently demonstrated that pulsed electron decoupling using frequency-chirped microwaves improves MAS DNP experiments by partially attenuating detrimental hyperfine interactions. The continued development of pulsed electron decoupling will enable a new suite of MAS DNP experiments that transfer polarization directly to observed spins. Time domain DNP transfers to nuclear spins in conjunction with pulsed electron decoupling is described as a viable avenue toward DNP-enhanced, high-resolution NMR spectroscopy over a range of temperatures from <6 to 320 K.

  • Dynamic Nuclear Polarization Nuclear Magnetic Resonance in Human Cells Using Fluorescent Polarizing Agents
    2018
    Co-Authors: Brice J. Albert, Chukun Gao, Erika L. Sesti, Edward P. Saliba, Nicholas Alaniva, Faith J. Scott, Snorri Th. Sigurdsson, Alexander B. Barnes
    Abstract:

    Solid state nuclear magnetic resonance (NMR) enables atomic-resolution characterization of the molecular structure and dynamics within complex heterogeneous samples, but it is typically insensitive. Dynamic nuclear polarization (DNP) increases the NMR Signal Intensity by orders of magnitude and can be performed in combination with magic angle spinning (MAS) for sensitive, high-resolution spectroscopy. Here we report MAS DNP experiments, for the first time, within intact human cells with >40-fold DNP enhancement and a sample temperature of

Samuel I Stupp - One of the best experts on this subject based on the ideXlab platform.

  • calcium induced morphological transitions in peptide amphiphiles detected by 19f magnetic resonance imaging
    ACS Applied Materials & Interfaces, 2017
    Co-Authors: Adam T Preslar, Laura M Lilley, Zer Keen Chia, Shanrong Zhang, Kohei Sato, Samuel I Stupp, Thomas J Meade
    Abstract:

    Misregulation of extracellular Ca2+ can indicate bone-related pathologies. New, noninvasive tools are required to image Ca2+ fluxes and fluorine magnetic resonance imaging (19F-MRI) is uniquely suited to this challenge. Here, we present three, highly fluorinated peptide amphiphiles that self-assemble into nanoribbons in buffered saline and demonstrate these nanostructures can be programmed to change 19F-NMR Signal Intensity as a function of Ca2+ concentration. We determined these nanostructures show significant reduction in 19F-NMR Signal as nanoribbon width increases in response to Ca2+, corresponding to 19F-MR image Intensity reduction. Thus, these peptide amphiphiles can be used to quantitatively image biologically relevant Ca2+ concentrations.

  • Calcium-Induced Morphological Transitions in Peptide Amphiphiles Detected by 19F‑Magnetic Resonance Imaging
    2017
    Co-Authors: Adam T Preslar, Laura M Lilley, Zer Keen Chia, Shanrong Zhang, Kohei Sato, Samuel I Stupp, Thomas J Meade
    Abstract:

    Misregulation of extracellular Ca2+ can indicate bone-related pathologies. New, noninvasive tools are required to image Ca2+ fluxes and fluorine magnetic resonance imaging (19F-MRI) is uniquely suited to this challenge. Here, we present three, highly fluorinated peptide amphiphiles that self-assemble into nanoribbons in buffered saline and demonstrate these nanostructures can be programmed to change 19F-NMR Signal Intensity as a function of Ca2+ concentration. We determined these nanostructures show significant reduction in 19F-NMR Signal as nanoribbon width increases in response to Ca2+, corresponding to 19F-MR image Intensity reduction. Thus, these peptide amphiphiles can be used to quantitatively image biologically relevant Ca2+ concentrations