scholarly journals A water molecule participates in the secondary structure of hyaluronan

1988 ◽  
Vol 254 (2) ◽  
pp. 489-493 ◽  
Author(s):  
F Heatley ◽  
J E Scott
Keyword(s):  
Secondary Structure ◽  
Water Molecule ◽  
High Field ◽  
Cell Membranes ◽  
Proton Exchange ◽  
Dimethyl Sulphoxide ◽  
Molecular Models ◽  
Saturation Transfer ◽  
Water Bridge ◽  
Space Filling

The structure of hyaluronan was investigated in water/dimethyl sulphoxide mixtures by using high-field n.m.r. and space-filling molecular models. The secondary structure previously established in detail in ‘dry’ dimethyl sulphoxide [Heatley, Scott & Hull (1984) Biochem. J. 220, 197-205] undergoes changes on addition of water, compatible with the incorporation of a water bridge between the uronate carboxylate and acetamido NH groups. Molecular models show that such a configuration is highly probable, and saturation-transfer experiments yield rates of NH proton exchange that support this proposed structure. The existence of two distinct stable configurations for hyaluronan, in water-rich and water-poor conditions respectively, may have biological implications, e.g. during its biosynthesis in cell membranes. There are extensive hydrophobic regions in both forms, which may be important for interactions with e.g., membranes, proteins and itself.

scholarly journals Detection of secondary structure in glycosaminoglycans via the1H n.m.r. signal of the acetamido NH group

1982 ◽  
Vol 207 (1) ◽  
pp. 139-144 ◽  
Author(s):  
J E Scott ◽  
F Heatley
Keyword(s):  
Secondary Structure ◽  
Chondroitin Sulphate ◽  
Heparan Sulphate ◽  
Periodate Oxidation ◽  
Close Approach ◽  
Dimethyl Sulphoxide ◽  
Space Filling ◽  
Keratan Sulphate ◽  
Inorganic Cations ◽  
Acid Glycosaminoglycans

Two simple methods for dissolving salts of acid glycosaminoglycans with inorganic cations (e.g. Li+ and Na+) in dry dimethyl sulphoxide are described. Complete n.m.r. spectra of, e.g., Na+ and Li+ salts of chondroitin sulphate and keratan sulphate were obtained on these solutions. In [2H6]dimethyl sulphoxide the NH resonance of 2-acetamido-2-deoxy hexosides is in the range 7.2-8.0 delta, but is downfield (8.3-9.3 delta) when the NH is H-bonded to -CO2-. Heparan sulphate shows two NH resonances, of which one (at 8.3 delta) is probably indicative of H-bonding. Space-filling models show that a very close approach of NH to -CO2- across the alpha-glucosaminidic bond is possible, and a solution configuration for heparan sulphate is proposed. The n.m.r. results are entirely compatible with interpretations of periodate-oxidation kinetics, based on H-bonded secondary structures present in hyaluronate and chondroitin sulphates, but not in dermatan (or keratan) sulphate.

Molecular Models of Cation and Water Molecule Bridges in Humic Substances

Soil Carbon ◽  
2014 ◽  
pp. 107-115 ◽  
Author(s):  
Daniel Tunega ◽  
Adelia J. A. Aquino ◽  
Georg Haberhauer ◽  
Hans Lischka ◽  
Gabriele E. Schaumann ◽  
...  
Keyword(s):  
Water Molecule ◽  
Humic Substances ◽  
Molecular Models

Isolated Monohydrates of a Model Peptide Chain: Effect of a First Water Molecule on the Secondary Structure of a Capped Phenylalanine

2011 ◽  
Vol 133 (11) ◽  
pp. 3931-3942 ◽  
Author(s):  
Himansu S. Biswal ◽  
Yohan Loquais ◽  
Benjamin Tardivel ◽  
Eric Gloaguen ◽  
Michel Mons
Keyword(s):  
Secondary Structure ◽  
Water Molecule ◽  
Peptide Chain ◽  
Model Peptide

Molecular Orientation of Phospholipid Langmuir-Blodgett Films

2006 ◽  
Vol 517 ◽  
pp. 65-68
Author(s):  
Khaulah Sulaiman ◽  
Wan Haliza Abd Majid ◽  
Muhamad Rasat Muhamad
Keyword(s):  
Fourier Transform ◽  
Molecular Orientation ◽  
Molecular Organization ◽  
Molecular Models ◽  
Space Filling ◽  
Lb Films ◽  
Langmuir Blodgett ◽  
Solid Substrates ◽  
Infra Red ◽  
Langmuir Blodgett Films

The molecular organization of the phospholipids Langmuir-Blodgett (LB) films on solid substrates has been studied via Fourier Transform Infra Red (FTIR) spectroscopy. In this study, the formation of well organized ultra thin LB films of phospholipid molecules has been performed by depositing the monolayer onto the solid substrates of silicon wafer. The space filling molecular models of two types of phospholipids have been proposed on the basis of the FTIR spectra.

scholarly journals Quantifying amide proton exchange rate and concentration in chemical exchange saturation transfer imaging of the human brain

NeuroImage ◽  
2019 ◽  
Vol 189 ◽  
pp. 202-213 ◽  
Author(s):  
Hye-Young Heo ◽  
Zheng Han ◽  
Shanshan Jiang ◽  
Michael Schär ◽  
Peter C.M. van Zijl ◽  
...  
Keyword(s):  
Exchange Rate ◽  
Human Brain ◽  
Chemical Exchange ◽  
Proton Exchange ◽  
Chemical Exchange Saturation Transfer ◽  
Amide Proton ◽  
Saturation Transfer ◽  
Amide Proton Exchange

scholarly journals Secondary Structure of Chondroitin Sulphate in Dimethyl Sulphoxide

1983 ◽  
Vol 130 (3) ◽  
pp. 491-495 ◽  
Author(s):  
John E. SCOTT ◽  
Frank HEATLEY ◽  
Malcolm N. JONES ◽  
Allan WILKINSON ◽  
Anthony H. OLAVESEN
Keyword(s):  
Secondary Structure ◽  
Chondroitin Sulphate ◽  
Dimethyl Sulphoxide
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