Direct and Indirect Determination of Binding Constants of Drug-Protein Complexes with Microparticles

1978 ◽  
Vol 67 (1) ◽  
pp. 107-109 ◽  
Author(s):  
Anita Kober ◽  
Bo Ekman ◽  
Ingvar Sjöholm
Keyword(s):  
Protein Complexes ◽  
Binding Constants ◽  
Indirect Determination

Protein–ligand and protein–protein interactions studied by electrospray ionization and mass spectrometry

2003 ◽  
Vol 31 (5) ◽  
pp. 985-989 ◽  
Author(s):  
W.I. Burkitt ◽  
P.J. Derrick ◽  
D. Lafitte ◽  
I. Bronstein
Keyword(s):  
Electrospray Ionization ◽  
Protein Interactions ◽  
Protein Complexes ◽  
High Vacuum ◽  
Binding Constants ◽  
Ion Cyclotron Resonance ◽  
Protein Protein Interactions ◽  
Small Proteins ◽  
Covalently Bound

Electrospray ionization has made possible the transference of non-covalently bound complexes from solution phase to high vacuum. In the process, a complex acquires a net charge and becomes amenable to measurement by MS. FTICR (Fourier-transform ion cyclotron resonance) MS allows these ions to be measured with sufficiently high resolution for the isotopomers of complexes of small proteins to be resolved from each other (true for complexes up to about 100 kDa for the most powerful FTICR instruments), which is of crucial significance in the interpretation of spectra. Results are presented for members of the S100 family of proteins, demonstrating how non-covalently bound complexes can be distinguished unambiguously from covalently bound species. Consideration relevant both to determination of binding constants in solution from the gas-phase results and to the elucidation of protein folding and unfolding in solution are discussed. The caveats inherent to the basic approach of using electrospray and MS to characterize protein complexes are weighed and evaluated.

scholarly journals On the preservation of non-covalent protein complexes during electrospray ionization

2016 ◽  
Vol 374 (2079) ◽  
pp. 20150377 ◽  
Author(s):  
Konstantin Chingin ◽  
Konstantin Barylyuk ◽  
Huanwen Chen
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Protein Complexes ◽  
Binding Constants ◽  
Mass Spectrometry Analysis ◽  
Ionization Mass ◽  
Application Range ◽  
Spectrometry Analysis ◽  
Droplet Chemistry

The application range of electrospray ionization mass spectrometry for the quantitative determination of stoichiometries and binding constants for non-covalent protein complexes is broadly discussed. The underlying fundamental question is whether or not the original molecular equilibrium can be preserved during the ionization process and be revealed by subsequent mass spectrometry analysis. Here, we take a new look at this question by discussing recent studies in droplet chemistry. This article is part of the themed issue ‘Quantitative mass spectrometry’.

Indirect Determination of Amikacin by Gold Nanoparticles as Redox Probe

2020 ◽  
Vol 17 ◽  
Author(s):  
Mansureh Alizadeh ◽  
Mandana Amiri ◽  
Abolfazl Bezaatpour
Keyword(s):  
Gold Nanoparticles ◽  
Bacterial Infections ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Cathodic Peak ◽  
Easy Method ◽  
Peak Current ◽  
Indirect Determination ◽  
Tract Infections

: Amikacin is an aminoglycoside antibiotic used for many gram-negative bacterial infections like infections in the urinary tract, infections in brain, lungs and abdomen. Electrochemical determination of amikacin is a challenge in electroanalysis because it shows no voltammetric peak at the surface of bare electrodes. In this approach, a very simple and easy method for indirect voltammetric determination of amikacin presented in real samples. Gold nanoparticles were electrodeposited at the surface of glassy carbon electrode in constant potential. The effect of several parameters such as time and potential of deposition, pH and scan rates on signal were studied. The cathodic peak current of Au3+ decreased with increasing amikacin concentration. Quantitative analysis of amikacin was performed using differential pulse voltammetry by following cathodic peak current of gold ions. Two dynamic linear ranges of 1.0 × 10−8–1.0 × 10-7 M and 5.0 × 10−7–1.0 × 10-3 M were obtained and limit of detection was estimated 3.0× 10−9 M. The method was successfully determined amikacin in pharmaceutical preparation and human serum. The effect of several interference in determination of amikacin was also studied.

Determination of Some Nitrophenols by Atomic Absorption Spectrometry (AAS) After Extraction of Ionic Associates Involving the Bipyridylocopper(II) or Phenanthrolinocopper(II) Complex

1994 ◽  
Vol 59 (10) ◽  
pp. 2227-2234 ◽  
Author(s):  
Václav Stužka ◽  
Jaromír Souček
Keyword(s):  
Molecular Weight ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Methyl Isobutyl Ketone ◽  
Absorption Spectrometry ◽  
Methyl Isobutyl ◽  
Isobutyl Ketone ◽  
Indirect Determination ◽  
Ionic Associates

A new method has been developed for the indirect determination of nitroso- and nitrophenols by atomic absorption spectrometry (AAS) after extraction of ionic associates involving bipyridylocopper(II) (CuDP) or phenanthrolinocopper(II) (CuPH) complexes. Nitrobenzene and methyl isobutyl ketone appeared to be suitable for the extraction. It was possible to determine several tenths to hundredths of a milligram of nitrophenol in a litre. Extractable associates with CuDP and CuPH are formed by phenols possessing two substituents or by higher molecular weight phenols such as naphthol or hydroxyquinoline. Monosubstituted phenols fail to form associates of this kind.

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