NMR h3 JNC’ Couplings Provide Comprehensive Geometrical Constraints for Protein H-bonds in Solution

Protein backbone H-bonds (>N–H···O–C<) show relationships between NMR h3JNC\u27 couplings measured in solution and H-bond geometry parameters seen in X-ray crystal structures. Assuming that the solution and crystal structure of protein backbone is the same, the h3JNC\u27 couplings can be calibrated to provide good estimates of both angular and radial H-bond parameters in a solution. The crucial premise of equality between the solution and the crystal structure of protein backbone we validated on the level of the NH-bonds orientation, by comparing the orientations inferred from X-ray crystal structures with the solution ones determined from NMR residual dipolar couplings

Halothane binds to druggable sites in the [Ca2+]4-calmodulin (CaM) complex, but does not inhibit [Ca2+]4-CaM activation of kinase

The mechanism(s) of volatile anesthetics (VA) are poorly understood. We used high resolution NMR spectroscopy to determine the structure of the halothane/calmodulin([Ca2+]4-CaM) complex, and found that halothane molecules bind in the druggable sites. We then examined whether VA binding to druggable sites in calmodulin would effect [Ca2+]4-CaM dependent activity of myosin light chain kinase. We used fluorescence assays to determine that VA effect [Ca2+]4-CaM activation of smooth-muscle-myosin-light-chain-kinase (smMLCK), but not the Kd of [Ca2+]4-CaM binding to skeletal-myosin-light-chain-kinase-peptide recognition sequence (skMLCKp). These results suggest that VA do not alter [Ca2+]4-CaM dependent MLCK activity via direct interactions with [Ca2+]4-CaM

Sinteza, NMR i DFT proračunavanja i ispitivanje antimikrobne aktivnosti Zn(II) kompleksa sa N-benziloksikarbonil-S-alaninom

In this study, the first complexes of Zn(II) with the N-benzyloxycar- bonyl-S-alaninato ligand (N-Boc-S-ala) were synthesized. The new complexes were characterized by elemental analysis, conductometric measurements, IR, 1H-NMR, 13C-NMR and 2D-NMR spectroscopy. On the basis of the experimental data, tetrahedral geometry of the Zn(II) complexes was proposed. A very good agreement between the NMR and DFT calculated data was obtained. Investigation of antimicrobial activity of the newly synthesized complexes was also performed. It was established that [Zn(N-Boc-S-ala)2] was selective and acts only on Candida albicans.U ovom radu su sintetizovani prvi kompleksi Zn(II) sa N-benziloksikarbonil-S-alaninato ligandom (N-Boc-S-ala). Kompleksi su okarakterisani elementalnom analizom, konduktometrijskim merenjem, IR, 1H-NMR, 13C-NMR i 2D-NMR spektroskopijom. Tetraedarska geometrija Zn(II) kompleksa pretpostavljena je na osnovu eksperimentalnih podataka. Dobijeno je veoma dobro slaganje između NMR i DFT podataka. Ispitivana je antimikrobna aktivnost novosintetizovanih kompleksa. Ustanovljeno je da je [Zn(N-Boc-S-ala)2] kompleks selektivan i da deluje samo na gljivu Candida albicans

JSCS–3764 Original scientific paper

Abstract: In this study, the first complexes of Zn(II) with the N-benzyloxycarbonyl-S-alaninato ligand (N-Boc-S-ala) were synthesized. The new complexes were characterized by elemental analysis, conductometric measurements, IR, 1H-NMR, 13C-NMR and 2D-NMR spectroscopy. On the basis of the experimental data, tetrahedral geometry of the Zn(II) complexes was proposed. A very good agreement between the NMR and DFT calculated data was obtained. Investigation of antimicrobial activity of the newly synthesized complexes was also performed. It was established that [Zn(N-Boc-S-ala) 2] was selective and acts only on Candida albicans

An apparatus for simultaneous determination of electrical conductivity and thermogravimetric curves of solid systems

A new apparatus for measurement of electrical conductivity during thermogravimetric analysis is described. Results of an investigation of the water-zeolite system in the interval -200° up to +450° prove the suitability of this apparatus in the investigation of gas-solid interaction mechanisms.On décrit un nouvel appareil pour la mesure de la conductivité électrique au cours de l'analyse thermogravimétrique. Les résultats des études effectuées sur des systèmes eauzéolithe entre −200 et +450° ont prouvé que l'appareil se prête aux études de mécanisme d'interaction gaz-solide.Eine neue Vorrichtung zur Messung der elektrischen Leitfähigkeit während der thermogravimetrischen Analyse wird beschrieben. Die Ergebnisse von an Wasser-Zeolyt-Systemen im Bereich von −200° bis +450° durchgeführten Untersuchungen bestätigen die Eignung des Apparates zum Studium des Mechanismus von Wechselwirkungen zwischen fester und GasPhase.Описан новый прибор д ля измерения электропроводности при проведении термогравиметричес кого анализа. Результ аты исследования систем ы вода-цеолит, проведе нного в области температур − 200° + 450° С, показали пригодность прибора для исследования механи зма газ – твердое веще ство