scholarly journals Structural determinants in a library of low molecular weight gelators

Soft Matter ◽  
2015 ◽  
Vol 11 (6) ◽  
pp. 1174-1181 ◽  
Author(s):  
Kyle L. Morris ◽  
Lin Chen ◽  
Alison Rodger ◽  
Dave J. Adams ◽  
Louise C. Serpell
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Circular Dichroism ◽  
Low Molecular Weight ◽  
Combined Approach ◽  
Structural Determinants ◽  
X Ray ◽  
Fibre Diffraction ◽  
Low Molecular Weight Gelators ◽  
Circular Dichroïsm

The structures of hydrogels formed by naphthalene dipeptide library were explored using a combined approach of electron microscopy, X-ray fibre diffraction and circular dichroism.

scholarly journals Characterization of the structure and composition of gecko adhesive setae

2005 ◽  
Vol 3 (8) ◽  
pp. 441-451 ◽  
Author(s):  
N.W Rizzo ◽  
K.H Gardner ◽  
D.J Walls ◽  
N.M Keiper-Hrynko ◽  
T.S Ganzke ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Electrophoretic Analysis ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pattern Characteristic ◽  
Additional Protein ◽  
Adhesive Materials

The ability of certain reptiles to adhere to vertical (and hang from horizontal) surfaces has been attributed to the presence of specialized adhesive setae on their feet. Structural and compositional studies of such adhesive setae will contribute significantly towards the design of biomimetic fibrillar adhesive materials. The results of electron microscopy analyses of the structure of such setae are presented, indicating their formation from aggregates of proteinaceous fibrils held together by a matrix and potentially surrounded by a limiting proteinaceous sheath. Microbeam X-ray diffraction analysis has shown conclusively that the only ordered protein constituent in these structures exhibits a diffraction pattern characteristic of β-keratin. Raman microscopy of individual setae, however, clearly shows the presence of additional protein constituents, some of which may be identified as α-keratins. Electrophoretic analysis of solubilized setal proteins supports these conclusions, indicating the presence of a group of low-molecular-weight β-keratins (14–20 kDa), together with α-keratins, and this interpretation is supported by immunological analyses.

scholarly journals The potential for circular dichroism as an additional facile and sensitive method of monitoring low-molecular-weight heparins and heparinoids

2009 ◽  
Vol 102 (11) ◽  
pp. 874-878 ◽  
Author(s):  
Scott Guimond ◽  
Joseph Holman ◽  
Jeremy Turnbull ◽  
Robert Lauder ◽  
David Fernig ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Circular Dichroism ◽  
Structural Changes ◽  
Principal Component ◽  
Rapid Analysis ◽  
Low Molecular Weight ◽  
Cd Spectra ◽  
Low Molecular Weight Heparins ◽  
Complementary Technique ◽  
Circular Dichroïsm

SummaryThe ultraviolet circular dichroism (CD) spectra of commercial low-molecular-weight heparins, heparinoids and other anticoagulant preparations have been recorded between 180 and 260 nm. Principal component analysis of the spectra allowed their differentiation into a number of groups related to the means of their production reflecting the structural changes introduced by each process. The findings suggest that CD provides a complementary technique for the rapid analysis of heparin preparations.

scholarly journals Circular dichroism studies of low molecular weight hydrogelators: The use of SRCD and addressing practical issues

Chirality ◽  
2018 ◽  
Vol 30 (6) ◽  
pp. 708-718
Author(s):  
Efstratios D. Sitsanidis ◽  
Carmen C. Piras ◽  
Bruce D. Alexander ◽  
Giuliano Siligardi ◽  
Tamás Jávorfi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Circular Dichroism ◽  
Low Molecular Weight ◽  
Circular Dichroïsm

scholarly journals Ultra-Low Molecular Weight Photoswitchable Hydrogelators

2020 ◽  
Author(s):  
Fayaz Larik ◽  
Lucy Fillbrook ◽  
Sandra Nurttila ◽  
Adam D Martin ◽  
Rhiannon P. Kuchel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Low Molecular Weight ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
Hydrogen Bonding Interactions ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Rhodamine B Dye

Photoswitchable arylazopyrozoles 2 and 3 form hydrogels at a concentration of 1.2% (w/v). With a molecular weight of 258.11 g/mol, these are the lowest known molecular weight hydrogelators that respond reversibly to light. Single-crystal X-ray structures show anisotropic aggregation of 2 and 3 is driven by in-plane hydrogen bonding interactions and 𝝅 - 𝝅 stacking. Photoswitching of 2 and 3 from the E- to the Z-form by 365 nm light results in a macrocopic gel→sol transition; nearly an order of magnitude reduction in the measured elastic and loss moduli. Cryogenic transmission electron microscopy suggests that the 29±7 nm wide sheets in the E-2 gel state narrow to 13±2 nm upon photoswitching to the predominantly Z-2 solution state. In the case of 2, photoswitching is reversible through cycles of 365 nm and 520 nm excitation with little fatigue. The release of a Rhodamine B dye encapsulated in gels formed from 2 and 3 can be accelerated more than 20-fold upon photoswitching with 365 nm light, demonstrating these materials are suitable for light-controlled cargo release.

Ultra-Low Molecular Weight Photoswitchable Hydrogelators

2020 ◽  
Author(s):  
Fayaz Larik ◽  
Lucy Fillbrook ◽  
Sandra Nurttila ◽  
Adam D Martin ◽  
Rhiannon P. Kuchel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Transmission Electron Microscopy ◽  
Low Molecular Weight ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
Hydrogen Bonding Interactions ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Rhodamine B Dye

Photoswitchable arylazopyrozoles 2 and 3 form hydrogels at a concentration of 1.2% (w/v). With a molecular weight of 258.11 g/mol, these are the lowest known molecular weight hydrogelators that respond reversibly to light. Single-crystal X-ray structures show anisotropic aggregation of 2 and 3 is driven by in-plane hydrogen bonding interactions and 𝝅 - 𝝅 stacking. Photoswitching of 2 and 3 from the E- to the Z-form by 365 nm light results in a macrocopic gel→sol transition; nearly an order of magnitude reduction in the measured elastic and loss moduli. Cryogenic transmission electron microscopy suggests that the 29±7 nm wide sheets in the E-2 gel state narrow to 13±2 nm upon photoswitching to the predominantly Z-2 solution state. In the case of 2, photoswitching is reversible through cycles of 365 nm and 520 nm excitation with little fatigue. The release of a Rhodamine B dye encapsulated in gels formed from 2 and 3 can be accelerated more than 20-fold upon photoswitching with 365 nm light, demonstrating these materials are suitable for light-controlled cargo release.

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