Simulation of Proteins Modified with a Fluorescent Label

2020 ◽  
pp. 289-313
Author(s):  
Zoe Chan ◽  
Yun-Chung Leung
Keyword(s):  
Fluorescent Label

scholarly journals An Advanced, Silicon-Based Substrate for Sensitive Nucleic Acids Detection

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3138 ◽  
Author(s):  
Salvatore Petralia ◽  
Nunzio Vicario ◽  
Giovanna Calabrese ◽  
Rosalba Parenti ◽  
Sabrina Conoci
Keyword(s):  
Limit Of Detection ◽  
Optical Signal ◽  
Fluorescent Label ◽  
Capture Probe ◽  
Microarray Technology ◽  
Probe Sequence ◽  
B Virus ◽  
Nucleic Acids Detection ◽  
Silicon Based ◽  
Dynamic Linear Range

Surface substrate and chemical functionalization are crucial aspects for the fabrication of the sensitive biosensor based on microarray technology. In this paper, an advanced, silicon-based substrate (A-MA) allowing enhancement of optical signal for microarray application is described. The substrate consists in a multilayer of Si/Al/SiO2 layers. The optical signal enhancement is reached by a combination of the mirror effect of Al film and the SiO2 thickness around 830 nm, which is able to reach the maximum of interference for the emission wavelength of the Cy5 fluorescent label. Moreover, SiO2 layer is suitable for the immobilization of single-strand DNA through standard silane chemistry, and probe densities of about 2000 F/um2 are reached. The microarray is investigated in the detection of HBV (Hepatitis B Virus) pathogen with analytical samples, resulting in a dynamic linear range of 0.05–0.5 nM, a sensitivity of about 18000 a.u. nM−1, and a Limit of Detection in the range of 0.031–0.043 Nm as a function of the capture probe sequence.

Chimeric virus-like particles of universal antigen epitopes of coronavirus and phage Qβ coat protein trigger the production of neutralizing antibodies

2021 ◽  
Vol 21 ◽  
Author(s):  
Yukun Guo ◽  
Ruizhen Guo ◽  
Yingxian Ma ◽  
Wenru Chang ◽  
Shengli Ming ◽  
...  
Keyword(s):  
Coat Protein ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Genetic Recombination ◽  
Fluorescent Label ◽  
Salting Out ◽  
Virus Like Particles ◽  
Chimeric Vlps ◽  
Universal Epitope

Background: Virus-like particles (VLPs) are non-genetic multimeric nanoparticles synthesized through in vitro or in vivo self-assembly of one or more viral structural proteins. Immunogenicity and safety of VLPs make them ideal candidates for vaccine development and efficient nanocarriers for foreign antigens or adjuvants to activate the immune system. Aims: The present study aimed to design and synthesize a chimeric VLP vaccine of the phage Qbeta (Qβ) coat protein presenting the universal epitope of the coronavirus. Methods: The RNA phage Qβ coat protein was designed and synthesized, denoted as Qbeta. The CoV epitope, a universal epitope of coronavirus, was inserted into the C-terminal of Qbeta using genetic recombination, which was designated as Qbeta-CoV. The N-terminal of Qbeta-CoV was successively inserted into the TEV restriction site using mCherry red fluorescent label and modified affinity-purified histidine label 6xHE, which was denoted as HE-Qbeta-CoV. Isopropyl β-D-1-thiogalactopyranoside (IPTG) assessment revealed the expression of Qbeta, Qbeta-CoV, and HE-Qbeta-CoV in the BL21 (DE3) cells. The fusion protein was purified by salting out using ammonium sulfate and affinity chromatography. The morphology of particles was observed using electron microscopy. The female BALB/C mice were immunized intraperitoneally with the Qbeta-CoV and HE-Qbeta-CoV chimeric VLPs vaccines. Their sera were collected for the detection of antibody level and antibody titer using ELISA. The serum is used for the neutralization test of the three viruses of MHV, PEDV, and PDCoV. Results: The results revealed that the fusion proteins Qbeta, Qbeta-CoV, and HE-Qbeta-CoV could all obtain successful expression. Particles with high purity were obtained after purification; the chimeric particles of Qbeta-CoV and HE-Qbeta-CoV were found to be similar to Qbeta particles in morphology and formed chimeric VLPs. In addition, two chimeric VLP vaccines induced specific antibody responses in mice, and the antibodies showed certain neutralizing activity. Conclusion: The successful construction of the chimeric VLPs of the phage Qβ coat protein presenting the universal epitope of coronavirus provides a vaccine form with potential clinical applications for the treatment of coronavirus disease.

A New Bromobimane Fluorescent Label for Anion Exchange Proteins

1989 ◽  
pp. 381-391
Author(s):  
N. S. Kosower ◽  
E. M. Kosower ◽  
A. E. Radkowsky ◽  
J. Zipser
Keyword(s):  
Anion Exchange ◽  
Fluorescent Label

CHARACTERIZATION OF DISORDERS OF PLATELET-VESSEL WALL INTERACTION IN AN AGGREGOMETER INCORPORATING BLOOD FLOW PAST AN ENDOTHELIAL CELL MONOLAYER

1987 ◽  
Author(s):  
E F Grabowski ◽  
K McKenny
Keyword(s):  
Endothelial Cell ◽  
Cell Monolayer ◽  
Fold Increase ◽  
Flow Chamber ◽  
Fluorescent Label ◽  
Endothelial Cell Monolayer ◽  
Flowing Blood ◽  
Normal States ◽  
Wall Interaction

Epi-fluorescence videomicroscopy permits real-time imaging of platelet (plt) adhesion-aggregation to a defined microinjury site of an endothelial cell monolayer (ECM) exposed to flowing blood. The fluorescent label is the TAB murine monoclonal antibody (courtesy of Dr. R.P. McEver) directed against human pit cp HB, together with a fluorescein-conjugated goat F(ab')2 against murine immunoglobulin. The combination assures specificity for pit membranes, yet leaves pit function intact. Bovine aortic ECM, grown on rectangular cover glasses, comprise one wall of a flow chamber mounted on a vertical microscope stage. A 6-0 sterile suture, drawn across the ECM in a direction transverse to flow, creates microinjuries of width 70 ± 15 (mean ± SD). Pit deposition is virtually absent upon intact and confluent regions of the ECM. On microinjury sites and at a shear rate of 270 sec-1, however, computer-enhanced images show pit adherence, aggregation, and embolization. Pretreatment of the ECM with 1.0 mMFC lysine acetyl salicylate, further, leads to a three-fold increase in aggregate length. ECM products inhibitable by aspirin, therefore, modulate adhesion-aggregation in disease and normal states under physiologic flow conditions. The Table shows that nercent coverage of the injury area, and mean aggregate length readily discriminate normal, post-aspirin, and von Willebrand's (vWD's) bloods. Aggregate length is reduced in vWD's blood to a greater degree (p<0.01) than by oral aspirin, while the latter is associated with a paradoxic increase (p<0.01) in single plt adhesion.

4-Bromomethyl-6,7-dimethoxycoumarin as a fluorescent label for carboxylic acids in chromatographic detection

1983 ◽  
Vol 269 ◽  
pp. 81-90 ◽  
Author(s):  
R. Farinotti ◽  
Ph. Siard ◽  
J. Bourson ◽  
S. Kirkiacharian ◽  
B. Valeur ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Fluorescent Label ◽  
Chromatographic Detection
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