Structure and Function of Bottlebrush Polymer: [i] Control of Confirmation by Stiff Main Chain and [ii] Anchoring Properties of Liquid Crystal Determined by Mobility of Side Chain

2021 ◽  
Vol 77 (4) ◽  
pp. P-170-P-177
Author(s):  
YUJI KINOSE
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Structure And Function ◽  
Side Chain ◽  
And Function

One Methylene Group in the Side Chain Can Alter by 90 Degrees the Orientation of a Main-Chain Liquid Crystal on a Unidirectional Substrate

2018 ◽  
Vol 7 (4) ◽  
pp. 453-458
Author(s):  
Yaroslav Odarchenko ◽  
Matthieu Defaux ◽  
Martin Rosenthal ◽  
Azaliia Akhkiamova ◽  
Polina Bovsunovskaya ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Side Chain ◽  
Methylene Group

Main-chain liquid-crystal elastomers versus side-chain liquid-crystal elastomers: similarities and differences in their mechanical properties

Soft Matter ◽  
2018 ◽  
Vol 14 (31) ◽  
pp. 6449-6462 ◽  
Author(s):  
D. Rogez ◽  
S. Krause ◽  
P. Martinoty
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystal ◽  
Main Chain ◽  
Poisson Ratio ◽  
Side Chain ◽  
Similarities And Differences ◽  
Liquid Crystal Elastomers

The shear and Young moduli, the poly-domain to mono-domain transition, the Poisson ratio and the supercritical or subcritical nature of main-chain and side-chain liquid-crystal elastomers are characterized with various mechanical experiments.

The structure and function of HPr

1998 ◽  
Vol 76 (2-3) ◽  
pp. 359-367 ◽  
Author(s):  
E Bruce Waygood
Keyword(s):  
Structure And Function ◽  
Side Chain ◽  
Phosphoryl Group ◽  
Phosphotransferase System ◽  
Tertiary Structures ◽  
E Coli ◽  
H Nmr ◽  
Early Protein ◽  
Alpha Beta ◽  
And Function

Histidine-containing phosphocarrier protein, HPr, was one of the early protein tertiary structures determined by two-dimensional 1H-NMR. Tertiary structures for HPrs from Escherichia coli, Bacillus subtilis, and Staphylococcus aureus have been obtained by 1H NMR and the overall folding pattern of HPr is highly conserved, a beta alpha beta beta alpha beta alpha arrangement of three alpha-helices overlaying a four-stranded beta-sheet. High-resolution structures for HPrs from E. coli and B. subtilis have been obtained using 15N- and 13C-labeled proteins. The first application of NMR to the understanding of the structure and function of HPr was to describe the phosphohistidine isomer, Ndelta1-P-histidine in S. aureus phospho-HPr, and the unusual pKas of the His-15 side chain. The pKa values for the His-15 imidazole from more recent studies are 5.4 for HPr and 7.8 for phospho-HPr from E. coli, for example. A consensus description of the active site is proposed for HPr and phospho-HPr. In HPr, His-15 has a defined conformation and N-caps helix A, and is thus affected by the helix dipole. His-15 undergoes a small conformational change upon phosphorylation, a movement to allow the phosphoryl group to be positioned such that it forms hydrogen bonds with the main chain amide nitrogens of residue 16 (not conserved) and Arg-17. Interactions between residue 12 side chain (not conserved: asparagine, serine, and threonine) and His-15, and between the Arg-17 guanidinium group and the phosphoryl group, are either weak or transitory.Key words: HPr, NMR, phosphoenolpyruvate:sugar phosphotransferase system, phosphohistidine, phosphoserine.

Properties of side chain liquid crystal polyesters containing chiral groups in the main chain

1996 ◽  
Vol 36 (24) ◽  
pp. 2921-2931 ◽  
Author(s):  
G. H. Mehl ◽  
F. Valvo ◽  
D. Lacey ◽  
J. W. Goodby ◽  
D. K. Das-Gupta
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Side Chain

scholarly journals Structure and function of an Arabidopsis thaliana sulfate transporter

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lie Wang ◽  
Kehan Chen ◽  
Ming Zhou
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Growth ◽  
Structure And Function ◽  
Regulatory Function ◽  
Side Chain ◽  
Sulfate Transporter ◽  
Dimer Formation ◽  
Anion Transporters ◽  
Stas Domain ◽  
And Function

AbstractPlant sulfate transporters (SULTR) mediate absorption and distribution of sulfate (SO42−) and are essential for plant growth; however, our understanding of their structures and functions remains inadequate. Here we present the structure of a SULTR from Arabidopsis thaliana, AtSULTR4;1, in complex with SO42− at an overall resolution of 2.8 Å. AtSULTR4;1 forms a homodimer and has a structural fold typical of the SLC26 family of anion transporters. The bound SO42− is coordinated by side-chain hydroxyls and backbone amides, and further stabilized electrostatically by the conserved Arg393 and two helix dipoles. Proton and SO42− are co-transported by AtSULTR4;1 and a proton gradient significantly enhances SO42− transport. Glu347, which is ~7 Å from the bound SO42−, is required for H+-driven transport. The cytosolic STAS domain interacts with transmembrane domains, and deletion of the STAS domain or mutations to the interface compromises dimer formation and reduces SO42− transport, suggesting a regulatory function of the STAS domain.

Structural and mechanistic studies on the peroxisomal oxygenase phytanoyl-CoA 2-hydroxylase (PhyH)

2007 ◽  
Vol 35 (5) ◽  
pp. 870-875 ◽  
Author(s):  
C.J. Schofield ◽  
M.A. McDonough
Keyword(s):  
Binding Sites ◽  
Point Mutations ◽  
Clinical Importance ◽  
Structure And Function ◽  
Side Chain ◽  
Mechanistic Studies ◽  
Pristanic Acid ◽  
Methyl Group ◽  
Refsum's Disease ◽  
And Function

Phytanic acid (PA) is an epimeric metabolite of the isoprenoid side chain of chlorophyll. Owing to the presence of its epimeric β-methyl group, PA cannot be metabolized by β-oxidation. Instead, it is metabolized in peroxisomes via α-oxidation to give pristanic acid, which is then oxidized by β-oxidation. PhyH (phytanoyl-CoA 2-hydroxylase, also known as PAHX), an Fe(II) and 2OG (2-oxoglutarate) oxygenase, catalyses hydroxylation of phytanoyl-CoA. Mutations of PhyH ablate its role in α-oxidation, resulting in PA accumulation and ARD (adult Refsum's disease). The structure and function of PhyH is discussed in terms of its clinical importance and unusual selectivity. Most point mutations of PhyH causing ARD cluster in two distinct groups around the Fe(II)- and 2OG-binding sites. Therapaeutic possibilities for the treatment of Refsum's disease involving PhyH are discussed.

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