Some Applications of Spin Labels in the Study of Serum Albumin and Biomembranes

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Gheorghe Benga ◽  
Ioana-Costina Dansoreanu ◽  
Maria Frangopol ◽  
Petre T. Frangopol
Keyword(s):  
Serum Albumin ◽  
Spin Label ◽  
Human Liver ◽  
Liver Microsomes ◽  
Egg Yolk ◽  
Spin Labeling ◽  
Spin Labels ◽  
Sh Groups ◽  
Low Concentrations ◽  
Computerized System

The main contributions of the groups lead by the two main authors (Gh.B and P.T.F.) in the field of spin labeling ESR in studies of serum albumin and of some biomembranes are briefly described, mentioning some priorities. These are: the description in Romanian publications of the methodology for using spin labels in studies of proteins and biomembranes using the type ART-6 ESR spectrometer manufactured in Romania; the adaptation to this ESR spectrometer of a computerized system for the acqusition and processing of data; the application of a newly synthesized spin label, reactive with SH groups, in the study of serum albumin; the finding of the effects of 25-hydroxycholesterol at low concentrations (0,5-10 %) on egg yolk lecitin; the finding of a relatively high fluidity of human liver microsomes.

scholarly journals A novel strategy for site selective spin-labeling to investigate bioactive entities by DNP and EPR spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin Herr ◽  
Max Fleckenstein ◽  
Martin Brodrecht ◽  
Mark V. Höfler ◽  
Henrike Heise ◽  
...  
Keyword(s):  
Solid State ◽  
Epr Spectroscopy ◽  
Spin Label ◽  
Tertiary Structure ◽  
Spin Labeling ◽  
Disulfide Bridge ◽  
Bioactive Molecules ◽  
Spin Labels ◽  
Time Saving ◽  
Site Selective

AbstractA novel specific spin-labeling strategy for bioactive molecules is presented for eptifibatide (integrilin) an antiplatelet aggregation inhibitor, which derives from the venom of certain rattlesnakes. By specifically labeling the disulfide bridge this molecule becomes accessible for analytical techniques such as Electron Paramagnetic Resonance (EPR) and solid state Dynamic Nuclear Polarization (DNP). The necessary spin-label was synthesized and inserted into the disulfide bridge of eptifibatide via reductive followed by insertion by a double Michael addition under physiological conditions. This procedure is universally applicable for disulfide containing biomolecules and is expected to preserve their tertiary structure with minimal change due to the small size of the label and restoring of the previous disulfide connection. HPLC and MS analysis show the successful introduction of the spin label and EPR spectroscopy confirms its activity. DNP-enhanced solid state NMR experiments show signal enhancement factors of up to 19 in 13C CP MAS experiments which corresponds to time saving factors of up to 361. This clearly shows the high potential of our new spin labeling strategy for the introduction of site selective radical spin labels into biomolecules and biosolids without compromising its conformational integrity for structural investigations employing solid-state DNP or advanced EPR techniques.

Deactivation of anti-cancer drug letrozole to a carbinol metabolite by polymorphic cytochrome P450 2A6 in human liver microsomes

Xenobiotica ◽  
2009 ◽  
Vol 00 (00) ◽  
pp. 090901052053001-8
Author(s):  
K. Murai ◽  
H. Yamazaki ◽  
K. Nakagawa ◽  
R. Kawai ◽  
T. Kamataki
Keyword(s):  
Cytochrome P450 ◽  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Cancer Drug ◽  
Anti Cancer ◽  
Cytochrome P450 2A6

Selegiline Metabolism and Cytochrome P450 Enzymes:In vitro Study in Human Liver Microsomes*

2000 ◽  
Vol 86 (5) ◽  
pp. 215-221 ◽  
Author(s):  
Paivi Taavitsainen ◽  
Markku Anttila ◽  
Leena Nyman ◽  
Hari Karnani ◽  
Jarmo S. Salonen ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Vitro Study

scholarly journals Nontargeted Metabolomics by High-Resolution Mass Spectrometry to Study the In Vitro Metabolism of a Dual Inverse Agonist of Estrogen-Related Receptors β and γ, DN203368

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 776
Author(s):  
Sin-Eun Kim ◽  
Seung-Bae Ji ◽  
Euihyeon Kim ◽  
Minseon Jeong ◽  
Jina Kim ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Human Liver ◽  
High Resolution Mass Spectrometry ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Rat Liver Microsomes ◽  
High Resolution Mass ◽  
Resolution Mass

DN203368 ((E)-3-[1-(4-[4-isopropylpiperazine-1-yl]phenyl) 3-methyl-2-phenylbut-1-en-1-yl] phenol) is a 4-hydroxy tamoxifen analog that is a dual inverse agonist of estrogen-related receptor β/γ (ERRβ/γ). ERRγ is an orphan nuclear receptor that plays an important role in development and homeostasis and holds potential as a novel therapeutic target in metabolic diseases such as diabetes mellitus, obesity, and cancer. ERRβ is also one of the orphan nuclear receptors critical for many biological processes, such as development. We investigated the in vitro metabolism of DN203368 by conventional and metabolomic approaches using high-resolution mass spectrometry. The compound (100 μM) was incubated with rat and human liver microsomes in the presence of NADPH. In the metabolomic approach, the m/z value and retention time information obtained from the sample and heat-inactivated control group were statistically evaluated using principal component analysis and orthogonal partial least-squares discriminant analysis. Significant features responsible for group separation were then identified using tandem mass spectra. Seven metabolites of DN203368 were identified in rat liver microsomes and the metabolic pathways include hydroxylation (M1-3), N-oxidation (M4), N-deisopropylation (M5), N,N-dealkylation (M6), and oxidation and dehydrogenation (M7). Only five metabolites (M2, M3, and M5-M7) were detected in human liver microsomes. In the conventional approach using extracted ion monitoring for values of mass increase or decrease by known metabolic reactions, only five metabolites (M1-M5) were found in rat liver microsomes, whereas three metabolites (M2, M3, and M5) were found in human liver microsomes. This study revealed that nontargeted metabolomics combined with high-resolution mass spectrometry and multivariate analysis could be a more efficient tool for drug metabolite identification than the conventional approach. These results might also be useful for understanding the pharmacokinetics and metabolism of DN203368 in animals and humans.

scholarly journals Roles of cytochrome P450 2A6 in the oxidation of flavone, 4´-hydroxyflavone, and 4´-, 3´-, and 2´-methoxyflavones by human liver microsomes

Xenobiotica ◽  
2021 ◽  
pp. 1-47
Author(s):  
Haruna Nagayoshi ◽  
Norie Murayama ◽  
Shigeo Takenaka ◽  
Vitchan Kim ◽  
Donghak Kim ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Cytochrome P450 2A6

scholarly journals Pyrrolidinyl Synthetic Cathinones α-PHP and 4F-α-PVP Metabolite Profiling Using Human Hepatocyte Incubations

2020 ◽  
Vol 22 (1) ◽  
pp. 230
Author(s):  
Jeremy Carlier ◽  
Xingxing Diao ◽  
Raffaele Giorgetti ◽  
Francesco P. Busardò ◽  
Marilyn A. Huestis
Keyword(s):  
Metabolite Profiling ◽  
Human Liver ◽  
Liver Microsomes ◽  
Drug Market ◽  
Metabolite Profile ◽  
Illegal Drug ◽  
Human Hepatocyte ◽  
Synthetic Cathinones ◽  
Metabolic Fate ◽  
Analytical Standards

For more than ten years, new synthetic cathinones (SCs) mimicking the effects of controlled cocaine-like stimulants have flooded the illegal drug market, causing numerous intoxications and fatalities. There are often no data on the pharmacokinetics of these substances when they first emerge onto the market. However, the detection of SC metabolites is often critical in order to prove consumption in clinical and forensic settings. In this research, the metabolite profile of two pyrrolidinyl SCs, α-pyrrolidinohexaphenone (α-PHP) and 4′′-fluoro-α-pyrrolidinovalerophenone (4F-α-PVP), were characterized to identify optimal intake markers. Experiments were conducted using pooled human hepatocyte incubations followed by liquid chromatography–high-resolution tandem mass spectrometry and data-mining software. We suggest α-PHP dihydroxy-pyrrolidinyl, α-PHP hexanol, α-PHP 2′-keto-pyrrolidinyl-hexanol, and α-PHP 2′-keto-pyrrolidinyl as markers of α-PHP use, and 4F-α-PVP dihydroxy-pyrrolidinyl, 4F-α-PVP hexanol, 4F-α-PVP 2′-keto-pyrrolidinyl-hexanol, and 4F-α-PVP 2′-keto-pyrrolidinyl as markers of 4F-α-PVP use. These results represent the first data available on 4F-α-PVP metabolism. The metabolic fate of α-PHP was previously studied using human liver microsomes and urine samples from α-PHP users. We identified an additional major metabolite (α-PHP dihydroxy-pyrrolidinyl) that might be crucial for documenting exposure to α-PHP. Further experiments with suitable analytical standards, which are yet to be synthesized, and authentic specimens should be conducted to confirm these results.

Exploration of inhibition potential of isoniazid and its metabolites towards CYP2E1 in human liver microsomes through LC-MS/MS analysis

2021 ◽  
pp. 114223
Author(s):  
Ankit Balhara ◽  
Avinash Kumar ◽  
Suryakant Kumar ◽  
Samiulla Dodheri Syed ◽  
Sanjeev Giri ◽  
...  
Keyword(s):  
Human Liver ◽  
Liver Microsomes ◽  
Human Liver Microsomes ◽  
Ms Analysis
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