Unequivocal Determination of Site-Specific Protein Disulfide Bond Reduction Potentials by Top-Down FTICR MS: Characterization of the N- and C-Terminal Redox-Active Sites in Human Thioredoxin 1

2013 ◽  
Vol 85 (19) ◽  
pp. 9164-9172 ◽  
Author(s):  
Jenna Scotcher ◽  
Benjamin J. Bythell ◽  
Alan G. Marshall
Keyword(s):  
Active Sites ◽  
Specific Protein ◽  
Site Specific ◽  
Fticr Ms ◽  
Reduction Potentials ◽  
Redox Active ◽  
Thioredoxin 1 ◽  
Protein Disulfide

scholarly journals Conjugate of Thiol and Guanidyl Units with Oligoethylene Glycol Linkage for Manipulation of Oxidative Protein Folding

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 879
Author(s):  
Shunsuke Okada ◽  
Motonori Matsusaki ◽  
Masaki Okumura ◽  
Takahiro Muraoka
Keyword(s):  
Protein Folding ◽  
Active Sites ◽  
Biological Process ◽  
Thiol Group ◽  
Native Conformation ◽  
Thiol Compounds ◽  
Oxidative Protein Folding ◽  
Redox Active ◽  
A Cell ◽  
Protein Disulfide

Oxidative protein folding is a biological process to obtain a native conformation of a protein through disulfide-bond formation between cysteine residues. In a cell, disulfide-catalysts such as protein disulfide isomerase promote the oxidative protein folding. Inspired by the active sites of the disulfide-catalysts, synthetic redox-active thiol compounds have been developed, which have shown significant promotion of the folding processes. In our previous study, coupling effects of a thiol group and guanidyl unit on the folding promotion were reported. Herein, we investigated the influences of a spacer between the thiol group and guanidyl unit. A conjugate between thiol and guanidyl units with a diethylene glycol spacer (GdnDEG-SH) showed lower folding promotion effect compared to the thiol–guanidyl conjugate without the spacer (GdnSH). Lower acidity and a more reductive property of the thiol group of GdnDEG-SH compared to those of GdnSH likely resulted in the reduced efficiency of the folding promotion. Thus, the spacer between the thiol and guanidyl groups is critical for the promotion of oxidative protein folding.

scholarly journals Determination of Site-Specific (Deuterium/Hydrogen) Ratios in Vanillin by 2H-NuclearMagnetic Resonance Spectrometry: Collaborative Study

2007 ◽  
Vol 90 (1) ◽  
pp. 187-195 ◽  
Author(s):  
Eric Jamin ◽  
Frédérique Martin ◽  
Gilles G Martin ◽  
I Billault ◽  
A -I Blanch-Cortès ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Collaborative Study ◽  
Official Method ◽  
Site Specific ◽  
Hydrogen Position ◽  
Nmr Spectrometry ◽  
Measuring Site ◽  
Commercial Sources

Abstract The results of collaborative study are reported for a method that determines the site-specific isotope ratios of deuterium/hydrogen (D/H)i in vanillin by deuterium-nuclear magnetic resonance (2H-NMR) spectrometry. This method allows characterization of all the main commercial sources of commercial vanillin and detection of undeclared mixtures. It is based on the fact that the amounts of deuterium at various positions in the vanillin molecule are significantly different from one source to another. Vanillin is dissolved in acetonitrile and analyzed with a high-field NMR spectrometer fitted with a deuterium probe and a fluorine lock. The proportions of isotopomers monodeuterated at each hydrogen position of the molecule are recorded, and the corresponding (D/H) ratios are determined by using a calibrated reference. Nine laboratories analyzed 5 materials supplied as blind duplicates (1 natural vanillin from vanilla beans, 2 synthetic vanillins from guaiacol, 1 semisynthetic vanillin from lignin, and a mixture of natural and synthetic vanillins). The precision of the method for measuring site-specific ratios was as follows: for (D/H)1 the within-laboratory standard deviation (sr) values ranged from 2.2 to 5.8 ppm, and the among-laboratories standard deviation (sR) values ranged from 3.6 to 5.1 ppm; for (D/H)3 the sr values ranged from 1.7 to 3.2 ppm, and the sR values ranged from 2.4 to 3.7 ppm; for (D/H)4 the sr values ranged from 2.3 to 6.2 ppm, and the sR values ranged from 2.4 to 6.4 ppm; for (D/H)5 the sr values ranged from 0.8 to 2.7 ppm, and the sR values ranged from 0.9 to 2.3 ppm. It was shown that these values allow a satisfactory discrimination between vanillin sources. Therefore, the Study Director recommends the method for adoption as a First Action Official Method by AOAC INTERNATIONAL.

scholarly journals Sensitive and fast characterization of site-specific protein glycosylation with capillary electrophoresis coupled to mass spectrometry

Talanta ◽  
2018 ◽  
Vol 179 ◽  
pp. 22-27 ◽  
Author(s):  
Yanyan Qu ◽  
Liangliang Sun ◽  
Guijie Zhu ◽  
Zhenbin Zhang ◽  
Elizabeth H. Peuchen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Capillary Electrophoresis ◽  
Specific Protein ◽  
Protein Glycosylation ◽  
Site Specific

Molecular Characterization of a Pancreas-Specific Protein Disulfide Isomerase, PDIp

1997 ◽  
Vol 16 (3) ◽  
pp. 269-274 ◽  
Author(s):  
MARK G. DESILVA ◽  
ABNER LOUIS NOTKINS ◽  
MICHAEL S. LAN
Keyword(s):  
Molecular Characterization ◽  
Protein Disulfide Isomerase ◽  
Specific Protein ◽  
Disulfide Isomerase ◽  
Protein Disulfide

Characterization of a site-specific PEGylated analog of exendin-4 and determination of the PEGylation site

2013 ◽  
Vol 454 (1) ◽  
pp. 553-558 ◽  
Author(s):  
Xiaowei Qian ◽  
Hongxia Dong ◽  
Hong Tian ◽  
Yue Tong ◽  
Linfeng Guo ◽  
...  
Keyword(s):  
Site Specific ◽  
A Site

scholarly journals How Reliable Is the Electrochemical Readout of MIP Sensors?

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2677 ◽  
Author(s):  
Aysu Yarman ◽  
Frieder W. Scheller
Keyword(s):  
Specific Binding ◽  
In Situ Characterization ◽  
Faradaic Current ◽  
Diffusional Permeability ◽  
Redox Active ◽  
Nonspecific Interactions ◽  
Target Binding

Electrochemical methods offer the simple characterization of the synthesis of molecularly imprinted polymers (MIPs) and the readouts of target binding. The binding of electroinactive analytes can be detected indirectly by their modulating effect on the diffusional permeability of a redox marker through thin MIP films. However, this process generates an overall signal, which may include nonspecific interactions with the nonimprinted surface and adsorption at the electrode surface in addition to (specific) binding to the cavities. Redox-active low-molecular-weight targets and metalloproteins enable a more specific direct quantification of their binding to MIPs by measuring the faradaic current. The in situ characterization of enzymes, MIP-based mimics of redox enzymes or enzyme-labeled targets, is based on the indication of an electroactive product. This approach allows the determination of both the activity of the bio(mimetic) catalyst and of the substrate concentration.

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