scholarly journals Dynamic behaviour of oxidized glutathione in solution investigated by nuclear magnetic resonance

1993 ◽  
Vol 71 (4) ◽  
pp. 506-511
Author(s):  
Claudio Rossi ◽  
Alessandro Donati ◽  
Sergio Ulgiati ◽  
Maria Rosaria Sansoni
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Biological Activity ◽  
Magnetic Resonance ◽  
Spin Label ◽  
Molecular Motion ◽  
Dynamic Behaviour ◽  
Oxidized Glutathione ◽  
Biological Functions ◽  
Conformational Properties ◽  
Structure In Solution

In view of the important biological functions of oxidized glutathione (GSSG), we investigated the correlation between dynamic and conformational properties and biological activity. Anisotropic molecular motion characterizes different GSSG molecular districts. This information, obtained by NMR carbon relaxation investigations, suggests that the peptide does not independently assume any stable structure in solution. Analysis of the effects of the addition of a stable spin label to the solution confirmed the absence of conformation of GSSG in D2O. Moreover, the paramagnetic effects observed on proton and carbon nuclei of oxidized glutathione suggest that the dipolar term is the main source of paramagnetic relaxation.

scholarly journals N,N-Bis(Hexyl α-d-Acetylmannosyl) Acrylamide

Molbank ◽  
10.3390/m1255 ◽  
2021 ◽  
Vol 2021 (3) ◽  
pp. M1255
Author(s):  
Atsushi Miyagawa ◽  
Shinya Ohno ◽  
Hatsuo Yamamura
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Side Reaction ◽  
Resonance Spectroscopy ◽  
Biological Functions ◽  
Unknown Compound ◽  
Acrylamide Monomer

Glycosyl monomers for the assembly of multivalent ligands are typically synthesized using carbohydrates with biological functions and polymerizable functional groups such as acrylamide or styrene introduced into the carbohydrate aglycon, and monomers polymerized using a radical initiator. Herein, we report the acryloylation of 6-aminohexyl α-mannoside and its conversion into the glycosyl monomer bearing an acrylamide group. The general acryloylation procedure afforded the desired N-hexyl acetylmannosyl acrylamide monomer as well as an unexpected compound with a close Rf value. The compounds were separated and analyzed by nuclear magnetic resonance spectroscopy and mass spectrometry, which revealed the unknown compound to be the bivalent N,N-bis(hexyl α-d-acetylmannosyl) acrylamide monomer, which contains two hexyl mannose units and one acrylamide group. To the best of our knowledge, this side reaction has not previously been disclosed, and may be useful for the construction of multivalent sugar ligands.

Nuclear magnetic resonance characterization of the ring conformations of monosubstituted derivatives of 1,3-dioxa-5,6-benzocycloheptene

1983 ◽  
Vol 61 (1) ◽  
pp. 109-115 ◽  
Author(s):  
R. St-Amour ◽  
M. St-Jacques
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Substituent Effects ◽  
Steric Effects ◽  
Slow Exchange ◽  
Conformational Properties ◽  
Derivatives Of ◽  
Ring Conformations ◽  
Twist Boat

The conformational properties of 2-alkyl (Me, Et, i-Pr, and t-Bu) and 2-phenyl derivatives of 1,3-dioxa-5,6-benzocycloheptene (1) were studied by 13C dnmr. Analysis of slow exchange spectra at 100.6 MHz indicates that all derivatives except tert-butyl exist in an equilibrium of chair (major) and twist-boat (minor) conformations. Substituent effects on the position of the equilibrium are rationalized in terms of steric effects.

scholarly journals Differential Effects of ReplacingEscherichiacoli Ribosomal Protein L27 with Its Homologue from Aquifexaeolicus

2001 ◽  
Vol 183 (22) ◽  
pp. 6565-6572 ◽  
Author(s):  
Bruce A. Maguire ◽  
Anton V. Manuilov ◽  
Robert A. Zimmermann
Keyword(s):  
Growth Rate ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ribosomal Subunit ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Extreme Thermophile ◽  
Ribosomal Subunit Protein ◽  
And Function ◽  
Structure In Solution

ABSTRACT The rpmA gene, which encodes 50S ribosomal subunit protein L27, was cloned from the extreme thermophileAquifex aeolicus, and the protein was overexpressed and purified. Comparison of the A.aeolicus protein with its homologue fromEscherichia coli by circular dichroism analysis and proton nuclear magnetic resonance spectroscopy showed that it readily adopts some structure in solution that is very stable, whereas the E. coli protein is unstructured under the same conditions. A mutant of E.coli that lacks L27 was found earlier to be impaired in the assembly and function of the 50S subunit; both defects could be corrected by expression of E. coliL27 from an extrachromosomal copy of the rpmA gene. WhenA. aeolicus L27 was expressed in the same mutant, an increase in the growth rate occurred and the “foreign” L27 protein was incorporated into E. coliribosomes. However, the presence of A.aeolicus L27 did not promote 50S subunit assembly. Thus, while the A. aeolicus protein can apparently replace its E. coli homologue functionally in completed ribosomes, it does not assist in the assembly of E. coli ribosomes that otherwise lack L27. Possible explanations for this paradoxical behavior are discussed.

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