An In-Depth Study of Redox-Induced Conformational Changes in Charge Transport Characteristics of a Ferrocene-Alkanethiolate Molecular Electronic Junction: Temperature-Dependent Transition Voltage Spectroscopy Analysis

2016 ◽  
Vol 120 (6) ◽  
pp. 3564-3572 ◽  
Author(s):  
Hyunhak Jeong ◽  
Yeonsik Jang ◽  
Dongku Kim ◽  
Wang-Taek Hwang ◽  
Jun-Woo Kim ◽  
...  
1996 ◽  
Vol 75 (03) ◽  
pp. 515-519 ◽  
Author(s):  
Mark J Post ◽  
Anke N de Graaf-Bos ◽  
George Posthuma ◽  
Philip G de Groot ◽  
Jan J Sixma ◽  
...  

Summary Purpose. Thermal angioplasty alters the thrombogenicity of the arterial wall. In previous studies, platelet adhesion was found to increase after heating human subendothelium to 55° C and decrease after heating to 90° C. In the present electron microscopic study, the mechanism of this temperature-dependent platelet adhesion to the heated arterial wall is elucidated by investigating temperature-dependent conformational changes of von Willebrand factor (vWF) and collagen types I and III and the binding of vWF to heated collagen. Methods. Purified vWF and/or collagen was applied to electron microscopic grids and heated by floating on a salt-solution of 37° C, 55° C or 90° C for 15 s. After incubation with a polyclonal antibody against vWF and incubation with protein A/gold, the grids were examined by electron microscopy. Results. At 37° C, vWF was coiled. At 55° C, vWF unfolded, whereas heating at 90° C caused a reduction in antigenicity. Collagen fibers heated to 37° C were 60.3 ± 3.1 nm wide. Heating to 55° C resulted in the unwinding of the fibers, increasing the width to 87.5 ± 8.2 nm (p < 0.01). Heating to 90° C resulted in denatured fibers with an enlarged width of 85.1 ± 6.1 nm (p < 0.05). Heating of collagen to 55° C resulted in an increased vWF binding as compared to collagen heated to 37° C or to 90° C. Incubation of collagen with vWF, prior to heating, resulted in a vWF binding after heating to 55° C that was similar to the 37° C binding and a decreased binding after 90° C. Conclusions. After 55° C heating, the von Willebrand factor molecule unfolds and collagen types I and III exhibit an increased adhesiveness for von Willebrand factor. Heating to 90° C denatures von Willebrand factor and collagen. The conformation changes of von Willebrand factor and its altered binding to collagen type I and III may explain the increased and decreased platelet adhesion to subendothelium after 55° C and 90° C heating, respectively.


2018 ◽  
Author(s):  
Michael Luzuriaga ◽  
Raymond P. Welch ◽  
Madushani Dharmawardana ◽  
Candace Benjamin ◽  
Shaobo Li ◽  
...  

<div><div><div><p>Vaccines have an innate tendency to lose their structural conformation upon environmental and chemical stressors. A loss in conformation reduces the therapeutic ability to prevent the spread of a pathogen. Herein, we report an in-depth study of zeolitic imidazolate framework-8 (ZIF-8) and its ability to provide protection for a model viral vector against dena- turing conditions. The immunoassay and spectroscopy analysis together demonstrate enhanced thermal and chemical stability to the conformational structure of the encapsulated viral nanoparticle. The long-term biological activity of this virus-ZIF composite was investigated in animal models to further elucidate the integrity of the encapsulated virus, the bio-safety, and immunogenicity of the overall composite. Additionally, histological analysis found no observable tissue damage in the skin or vital organs in mice, following multiple subcutaneous administrations. This study shows that ZIF-based protein composites are strong candidates for improved preservation of proteinaceous drugs, are biocompatible, and capable of controlling the release and adsorption of drugs in vivo.</p></div></div></div>


2014 ◽  
Vol 16 (36) ◽  
pp. 19602-19607 ◽  
Author(s):  
Carlos Alberto Brito da Silva Júnior ◽  
José Fernando Pereira Leal ◽  
Vicente Ferrer Pureza Aleixo ◽  
Felipe A. Pinheiro ◽  
Jordan Del Nero

We investigate electronic transport in semiconductor–molecule–metal junctions consisting of a biphenyl molecule attached to a p-doped semiconductor and metallic carbon nanotubes.


2019 ◽  
Author(s):  
Minjoo Kim ◽  
Nicholas J. Sisco ◽  
Jacob K. Hilton ◽  
Camila M. Montano ◽  
Manuel A. Castro ◽  
...  

AbstractSensing and responding to temperature is crucial in biology. The TRPV1 ion channel is a well-studied heat-sensing receptor that is also activated by vanilloid compounds including capsaicin. Despite significant interest, the molecular underpinnings of thermosensing have remained elusive. The TRPV1 S1-S4 membrane domain couples chemical ligand binding to the pore domain during channel gating. However, the role of the S1-S4 domain in thermosensing is unclear. Evaluation of the isolated human TRPV1 S1-S4 domain by solution NMR, Far-UV CD, and intrinsic fluorescence shows that this domain undergoes a non-denaturing temperature-dependent transition with a high thermosensitivity. Further NMR characterization of the temperature-dependent conformational changes suggests the contribution of the S1-S4 domain to thermosensing shares features with known coupling mechanisms between this domain with ligand and pH activation. Taken together, this study shows that the TRPV1 S1-S4 domain contributes to TRPV1 temperature-dependent activation.


2012 ◽  
Vol 1 (1) ◽  
pp. Q4-Q7 ◽  
Author(s):  
Z. Liu ◽  
T. P. Chen ◽  
Y. Liu ◽  
M. Yang ◽  
J. I. Wong ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document