Convenient and straightforward synthesis of ibrutinib labeled by carbon-13 isotope is reported. Isotopically labeled building block is introduced in the last step of reaction sequence affording sufficient isolated yield (7%) of [13 C6 ]-ibrutinib calculated towards starting commercially available [13 C6 ]-bromobenzene.
There is inconsistent information regarding the size effects of exogenously given hyaluronan on its in vivo fate. The data are often biased by the poor quality of hyaluronan and non-ideal labelling strategies used for resolving exogenous/endogenous hyaluronan, which only monitor the label and not hyaluronan itself. To overcome these drawbacks and establish the pharmacokinetics of intravenous hyaluronan in relation to its Mw, 13C-labelled HA of five Mws from 13.6-1562 kDa was prepared and administered to mice at doses 25-50 mg kg-1. The elimination efficiency increased with decreasing Mw. Low Mw hyaluronan was rapidly eliminated as small hyaluronan fragments in urine, while high Mw hyaluronan exhibited saturable kinetics and complete metabolization within 48 h. All tested Mws exhibited a similar uptake by liver cells and metabolization into activated sugars. 13C-labelling combined with LC-MS provides an excellent approach to elucidating in vivo fate and biological activities of hyaluronan.
- MeSH
- cesty eliminace léčiva MeSH
- chrupavka metabolismus MeSH
- cyklická ADP-ribosa metabolismus MeSH
- intravenózní podání MeSH
- izotopové značení metody MeSH
- izotopy uhlíku chemie metabolismus farmakokinetika MeSH
- kosti a kostní tkáň metabolismus MeSH
- kyselina hyaluronová chemie metabolismus farmakokinetika MeSH
- molekulová hmotnost MeSH
- myši inbrední BALB C MeSH
- tkáňová distribuce MeSH
- uridindifosfát-N-acetylglukosamin metabolismus MeSH
- uridindifosfátglukosa metabolismus MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
A dodecadepsipeptide valinomycin (VLM) has been most recently reported to be a potential anti-coronavirus drug that could be efficiently produced on a large scale. It is thus of importance to study solid-phase forms of VLM in order to be able to ensure its polymorphic purity in drug formulations. The previously available solid-state NMR (SSNMR) data are combined with the plane-wave DFT computations in the NMR crystallography framework. Structural/spectroscopical predictions (the PBE functional/GIPAW method) are obtained to characterize four polymorphs of VLM. Interactions which confer a conformational stability to VLM molecules in these crystalline forms are described in detail. The way how various structural factors affect the values of SSNMR parameters is thoroughly analyzed, and several SSNMR markers of the respective VLM polymorphs are identified. The markers are connected to hydrogen bonding effects upon the corresponding (13C/15N/1H) isotropic chemical shifts of (CO, Namid, Hamid, Hα) VLM backbone nuclei. These results are expected to be crucial for polymorph control of VLM and in probing its interactions in dosage forms.
- MeSH
- Betacoronavirus chemie izolace a purifikace metabolismus MeSH
- izotopy dusíku chemie MeSH
- izotopy uhlíku chemie MeSH
- koronavirové infekce patologie virologie MeSH
- krystalografie MeSH
- magnetická rezonanční spektroskopie metody MeSH
- pandemie MeSH
- valinomycin chemie metabolismus MeSH
- virová pneumonie patologie virologie MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
Gas chromatography (GC) is a commonly used technique in amino acid analysis (AAA). However, one of the requirements of the application of GC for AAA is a need for the polar analytes to be converted into their volatile, thermally stable derivatives. In the last two decades, alkyl chloroformates (RCFs) have become attractive derivatization reagents. The reagents react immediately with most amino acid functional groups in aqueous matrices, and the process can easily be coupled with liquid-liquid extraction of the resulting less polar derivatives into immiscible organic phase. Here we describe a simple protocol for in situ derivatization of amino acids with heptafluorobutyl chloroformate (HFBCF) followed by subsequent chiral as well as nonchiral GC/MS (mass spectrometric) analysis on a respective nonpolar fused silica and an enantioselective Chirasil-Val capillary column.
- MeSH
- aminokyseliny krev chemie izolace a purifikace MeSH
- deuterium analýza chemie MeSH
- extrakce kapalina-kapalina přístrojové vybavení metody MeSH
- fluorokarbony chemie MeSH
- formiáty chemie MeSH
- izotopy uhlíku analýza chemie MeSH
- kalibrace MeSH
- lidé MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí přístrojové vybavení metody MeSH
- stereoizomerie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We report a new NMR-scale purification procedure for two recombinant wild type fragments of the stromal interaction molecule 1 (STIM1). This protein acts as a calcium sensor in the endoplasmic reticulum (ER) and extends into the cytosol accumulating at ER - plasma membrane (PM) junctions upon calcium store depletion ultimately leading to activation of the Orai/CRAC channel. The functionally relevant cytosolic part of STIM1 consists of three coiled coil domains, which are mainly involved in intra- and inter-molecular homomeric interactions as well as coupling to and gating of CRAC channels. The optimized one-step rapid purification procedure for two 15N,13C isotope-labeled cytosolic coiled coil fragments, which avoids the problems of previous approaches. The high yields of soluble well folded 15N,13C isotope-labeled cytosolic coiled coil fragments followed by detergent screening provide for initial NMR characterization of these domains. The longer 30.5 kDa fragment represents the largest STIM1 wild type fragment that has been recombinantly prepared and characterized in solution without need for mutation or refolding.
- MeSH
- chromatografie afinitní MeSH
- dynamický rozptyl světla MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- izotopové značení MeSH
- izotopy dusíku chemie izolace a purifikace MeSH
- izotopy uhlíku chemie izolace a purifikace MeSH
- lidé MeSH
- nádorové proteiny chemie izolace a purifikace MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- protein STIM1 chemie izolace a purifikace MeSH
- proteinové domény MeSH
- rekombinantní proteiny chemie izolace a purifikace MeSH
- rozpustnost MeSH
- sbalování proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Protontherapy is hadrontherapy's fastest-growing modality and a pillar in the battle against cancer. Hadrontherapy's superiority lies in its inverted depth-dose profile, hence tumour-confined irradiation. Protons, however, lack distinct radiobiological advantages over photons or electrons. Higher LET (Linear Energy Transfer) 12C-ions can overcome cancer radioresistance: DNA lesion complexity increases with LET, resulting in efficient cell killing, i.e. higher Relative Biological Effectiveness (RBE). However, economic and radiobiological issues hamper 12C-ion clinical amenability. Thus, enhancing proton RBE is desirable. To this end, we exploited the p + 11B → 3α reaction to generate high-LET alpha particles with a clinical proton beam. To maximize the reaction rate, we used sodium borocaptate (BSH) with natural boron content. Boron-Neutron Capture Therapy (BNCT) uses 10B-enriched BSH for neutron irradiation-triggered alpha particles. We recorded significantly increased cellular lethality and chromosome aberration complexity. A strategy combining protontherapy's ballistic precision with the higher RBE promised by BNCT and 12C-ion therapy is thus demonstrated.
- MeSH
- alfa částice terapeutické užití MeSH
- bor chemie terapeutické užití MeSH
- borohydridy chemie MeSH
- buněčná smrt účinky záření MeSH
- chromozomální aberace účinky záření MeSH
- cyklotrony MeSH
- DNA nádorová genetika metabolismus účinky záření MeSH
- fluorescenční barviva chemie MeSH
- izotopy uhlíku chemie MeSH
- karyotypizace MeSH
- kombinovaná terapie přístrojové vybavení metody MeSH
- lidé MeSH
- lineární přenos energie MeSH
- nádorové buněčné linie MeSH
- nádory prostaty patologie radioterapie MeSH
- neutrony * MeSH
- poškození DNA MeSH
- protonová terapie * přístrojové vybavení metody MeSH
- relativní biologická účinnost MeSH
- sulfhydrylové sloučeniny chemie MeSH
- terapie metodou neutronového záchytu (bor-10) přístrojové vybavení metody MeSH
- vztah dávky záření a odpovědi MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
MAS solid-state NMR is capable of determining structures of protonated solid proteins using proton-detected experiments. These experiments are performed at MAS rotation frequency of around 110 kHz, employing 0.5 mg of material. Here, we compare 1H, 13C correlation spectra obtained from protonated and deuterated microcrystalline proteins at MAS rotation frequency of 111 kHz, and show that the spectral quality obtained from deuterated samples is superior to those acquired using protonated samples in terms of resolution and sensitivity. In comparison to protonated samples, spectra obtained from deuterated samples yield a gain in resolution on the order of 3 and 2 in the proton and carbon dimensions, respectively. Additionally, the spectrum from the deuterated sample yields approximately 2-3 times more sensitivity compared to the spectrum of a protonated sample. This gain could be further increased by a factor of 2 by making use of stereospecific precursors for biosynthesis. Although the overall resolution and sensitivity of 1H, 13C correlation spectra obtained using protonated solid samples with rotation frequencies on the order of 110 kHz is high, the spectral quality is still poor when compared to the deuterated samples. We believe that experiments involving large protein complexes in which sensitivity is limiting will benefit from the application of deuteration schemes.
Sequence dependence of (13) C and (15) N chemical shifts in the receiver domain of CKI1 protein from Arabidopsis thaliana, CKI1RD , and its complexed form, CKI1RD •Mg(2+), was studied by means of MD/DFT calculations. MD simulations of a 20-ns production run length were performed. Nine explicitly hydrated structures of increasing complexity were explored, up to a 40-amino-acid structure. The size of the model necessary depended on the type of nucleus, the type of amino acid and its sequence neighbors, other spatially close amino acids, and the orientation of amino acid NH groups and their surface/interior position. Using models covering a 10 and a 15 Å environment of Mg(2+), a semi-quantitative agreement has been obtained between experiment and theory for the V67-I73 sequence. The influence of Mg(2+) binding was described better by the 15 Å as compared to the 10 Å model. Thirteen chemical shifts were analyzed in terms of the effect of Mg(2+) insertion and geometry preparation. The effect of geometry was significant and opposite in sign to the effect of Mg(2+) binding. The strongest individual effects were found for (15) N of D70, S74, and V68, where the electrostatics dominated; for (13) Cβ of D69 and (15) N of K76, where the influences were equal, and for (13) Cα of F72 and (13) Cβ of K76, where the geometry adjustment dominated. A partial correlation between dominant geometry influence and torsion angle shifts upon the coordination has been observed.
- MeSH
- hořčík chemie MeSH
- izotopy dusíku chemie MeSH
- izotopy uhlíku chemie MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- proteinkinasy chemie MeSH
- proteinové domény MeSH
- proteiny huseníčku chemie MeSH
- simulace molekulární dynamiky MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A pair of 4D NMR experiments for the backbone assignment of disordered proteins is presented. The experiments exploit (13)C direct detection and non-uniform sampling of the indirectly detected dimensions, and provide correlations of the aliphatic proton (H(α), and H(β)) and carbon (C(α), C(β)) resonance frequencies to the protein backbone. Thus, all the chemical shifts regularly used to map the transient secondary structure motifs in the intrinsically disordered proteins (H(α), C(α), C(β), C', and N) can be extracted from each spectrum. Compared to the commonly used assignment strategy based on matching the C(α) and C(β) chemical shifts, inclusion of the H(α) and H(β) provides up to three extra resonance frequencies that decrease the chance of ambiguous assignment. The experiments were successfully applied to the original assignment of a 12.8 kDa intrinsically disordered protein having a high content of proline residues (26 %) in the sequence.
Nuclear polyadenylated RNA-binding (Nab)3 protein is an RNA-binding protein that is involved in the poly(A) independent termination pathway. Here, we report the NMR spectral assignments of RNA-recognition motif (RRM) of Nab3. The assignment will allow performing NMR structural and RNA-binding studies of Nab3 with the aim to investigate its role in the poly(A) independent termination pathway.
- MeSH
- aminokyselinové motivy MeSH
- izotopy dusíku chemie MeSH
- izotopy uhlíku chemie MeSH
- jaderné proteiny chemie MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- proteiny vázající RNA chemie MeSH
- Saccharomyces cerevisiae - proteiny chemie MeSH
- Saccharomyces cerevisiae MeSH
- sekundární struktura proteinů MeSH
- vodík chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
