Conformational characterization of solid polypeptides by carbon-13 NMR recorded by the cross polarization-magic angle spinning method: conformation-dependent carbon-13 chemical shifts of oligo- and poly(γ-benzyl L-glutamates) and sequential copolymers of γ-benzyl and γ-methyl L-glutamates and qualitative evaluation of side-chain orientation

1984 ◽  
Vol 17 (8) ◽  
pp. 1472-1479 ◽  
Author(s):  
Akira Shoji ◽  
Takuo Ozaki ◽  
Hazime Saito ◽  
Ryoko Tabeta ◽  
Isao Ando
Keyword(s):  
Chemical Shifts ◽  
Qualitative Evaluation ◽  
Magic Angle Spinning ◽  
Side Chain ◽  
Magic Angle ◽  
Cross Polarization ◽  
Chain Orientation ◽  
Angle Spinning ◽  
Side Chain Orientation

Preparation, Characterization of Cellulose Fibers Grafting by β-Cyclodextrin and their Application for Antibacterial Products

2014 ◽  
Vol 936 ◽  
pp. 784-788 ◽  
Author(s):  
Chao Dong ◽  
Ying Ye ◽  
Li Ying Qian ◽  
Bei Hai He ◽  
Hui Ning Xiao
Keyword(s):  
Inclusion Complexes ◽  
Cellulose Fiber ◽  
Cellulose Fibers ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Food Chemistry ◽  
Cross Polarization ◽  
Angle Spinning ◽  
Cp Mas Nmr

Cyclodextrins (CDs) can form inclusion complexes with a variety of molecules making them very attractive in different areas, such as pharmaceutics, biochemistry, food chemistry and papermaking. In this communication the preparation of β-cyclodextrin-grafted cellulose fibers was carried out by reacting β-cyclodextrin with cellulose fiber via citric acid (CA). Both fourier transform infrared (FTIR) and cross polarization magic angle spinning solid state nuclear magnetic resonance (CP-MAS NMR) indicated that β-CDs had been chemically attached to cellulose backbone through the formation of ester bonds. Furthermore, the β-CD-grafted cellulose fibers formed inclusion complexes with ciprofloxacin hydrochloride (CipHCl). And the β-CD-grafted cellulose fibers loaded with CipHCl showed excellent antibacterial activity against E.coli and S.aureus.

scholarly journals Light-induced chromophore activity and signal transduction in phytochromes observed by 13C and 15N magic-angle spinning NMR

2008 ◽  
Vol 105 (40) ◽  
pp. 15229-15234 ◽  
Author(s):  
Thierry Rohmer ◽  
Christina Lang ◽  
Jon Hughes ◽  
Lars-Oliver Essen ◽  
Wolfgang Gärtner ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Chemical Shifts ◽  
Binding Pocket ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Cross Polarization ◽  
Water Network ◽  
Stable States ◽  
Modified Surface ◽  
Angle Spinning

Both thermally stable states of phytochrome, Pr and Pfr, have been studied by 13C and 15N cross-polarization (CP) magic-angle spinning (MAS) NMR using cyanobacterial (Cph1) and plant (phyA) phytochrome sensory modules containing uniformly 13C- and 15N-labeled bilin chromophores. Two-dimensional homo- and heteronuclear experiments allowed most of the 13C chemical shifts to be assigned in both states. Chemical shift differences reflect changes of the electronic structure of the cofactor at the atomic level as well as its interactions with the chromophore-binding pocket. The chromophore in cyanobacterial and plant phytochromes shows very similar features in the respective Pr and Pfr states. The data are interpreted in terms of a strengthened hydrogen bond at the ring D carbonyl. The red shift in the Pfr state is explained by the increasing length of the conjugation network beyond ring C including the entire ring D. Enhanced conjugation within the π-system stabilizes the more tensed chromophore in the Pfr state. Concomitant changes at the ring C propionate carboxylate and the ring D carbonyl are explained by a loss of hydrogen bonding to Cph1-His-290 and transmittance of conformational changes to the ring C propionate via a water network. These and other conformational changes may lead to modified surface interactions, e.g., along the tongue region contacting the bilin chromophore.

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