Behavior of supramolecular cross-links formed by host-guest interactions in hydrogels responding to water contents

1986 ◽

Vol 44 ◽

pp. 98-101

Author(s):

John M. Murray ◽

Rob Ward

Keyword(s):

Electron Microscopy ◽

Primary Motion ◽

Cryo Electron Microscopy ◽

Cross Links ◽

Cilia And Flagella

The eukaryotic flagellum is constructed from 11 parallel tubular elements arranged as 9 peripheral fibers (doublet microtubules) and 2 central fibers (singlet microtubules). The primary motion generating component has been found to be arranged as axially periodic “arms” bridging the adjacent doublets. The dynein, comprising the arms, has been isolated and characterized from several different cilia and flagella. Various radial and azimuthal cross-links stabilize the axially aligned microtubules, and probably play some role in controlling the form of the flagella beat cycle.

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Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156547 ◽

1989 ◽

Vol 47 ◽

pp. 912-913

Author(s):

S.K. Aggarwal

Keyword(s):

Alkaline Phosphatase ◽

Rat Kidney ◽

Light And Electron Microscopy ◽

Kidney Tissue ◽

Membrane Glycoproteins ◽

Electron Microscopic ◽

Before And After ◽

Interstrand Cross Links ◽

Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

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CROSS-LINKS IN POLYACETYLENE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1983387 ◽

1983 ◽

Vol 44 (C3) ◽

pp. C3-443-C3-446

Author(s):

C. T. White ◽

P. Brant ◽

M. L. Elert

Keyword(s):

Cross Links

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Bacterial Peptidoglycan Stapling with Functionalized D-Amino Acids

10.26434/chemrxiv.10248764.v1 ◽

2019 ◽

Author(s):

Sylvia L. Rivera ◽

Akbar Espaillat ◽

Arjun K. Aditham ◽

Peyton Shieh ◽

Chris Muriel-Mundo ◽

...

Keyword(s):

Cell Wall ◽

Clinical Success ◽

Bacterial Species ◽

Enzymatic Reaction ◽

Amino Acid Derivative ◽

Wall Structure ◽

Live Bacteria ◽

Cross Links ◽

Osmotic Lysis ◽

Bacterial Peptidoglycan

Transpeptidation reinforces the structure of cell wall peptidoglycan, an extracellular heteropolymer that protects bacteria from osmotic lysis. The clinical success of transpeptidase-inhibiting β-lactam antibiotics illustrates the essentiality of these cross-linkages for cell wall integrity, but the presence of multiple, seemingly redundant transpeptidases in many bacterial species makes it challenging to determine cross-link function precisely. Here we present a technique to covalently link peptide strands by chemical rather than enzymatic reaction. We employ bio-compatible click chemistry to induce triazole formation between azido- and alkynyl-D-alanine residues that are metabolically installed in the cell walls of Gram-positive and Gram-negative bacteria. Synthetic triazole cross-links can be visualized by substituting azido-D-alanine with azidocoumarin-D-alanine, an amino acid derivative that undergoes fluorescent enhancement upon reaction with terminal alkynes. Cell wall stapling protects the model bacterium Escherichia coli from β-lactam treatment. Chemical control of cell wall structure in live bacteria can provide functional insights that are orthogonal to those obtained by genetics.<br>

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Bonded Force Constant Derivation of Lysine-Arginine Cross-linked Advanced Glycation End-Products

10.26434/chemrxiv.5891602.v2 ◽

2018 ◽

Author(s):

Anthony Nash ◽

Nora H de Leeuw ◽

Helen L Birch

Keyword(s):

Molecular Dynamics ◽

Force Constant ◽

Computational Study ◽

Force Constants ◽

Quantum Mechanical ◽

Advanced Glycation ◽

Partial Charges ◽

Cross Links ◽

Complete Set ◽

Dynamics Simulations

<div> <div> <div> <p>The computational study of advanced glycation end-product cross- links remains largely unexplored given the limited availability of bonded force constants and equilibrium values for molecular dynamics force fields. In this article, we present the bonded force constants, atomic partial charges and equilibrium values of the arginine-lysine cross-links DOGDIC, GODIC and MODIC. The Hessian was derived from a series of <i>ab initio</i> quantum mechanical electronic structure calculations and from which a complete set of force constant and equilibrium values were generated using our publicly available software, ForceGen. Short <i>in vacuo</i> molecular dynamics simulations were performed to validate their implementation against quantum mechanical frequency calculations. </p> </div> </div> </div>

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Faculty Opinions recommendation of Association between collagen cross-links and trabecular microarchitecture properties of human vertebral bone.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1167976.630080 ◽

2009 ◽

Author(s):

Eleftherios Paschalis

Keyword(s):

Trabecular Microarchitecture ◽

Vertebral Bone ◽

Cross Links

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A review of the composition and evolution of hydrocarbon gases during solidification of the Ilímaussaq alkaline complex, South Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v190.5187 ◽

2001 ◽

pp. 159-166 ◽

Cited By ~ 6

Author(s):

Jens Konnerup-Madsen

Keyword(s):

Nepheline Syenite ◽

Subsequent Development ◽

High Water ◽

Vapour Phase ◽

Low Carbon ◽

Low Oxygen ◽

Alkaline Complex ◽

Hydrocarbon Gases ◽

Wide Range ◽

Water Contents

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Konnerup-Madsen, J. (2001). A review of the composition and evolution of hydrocarbon gases during solidification of the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 159-166. https://doi.org/10.34194/ggub.v190.5187 _______________ Fluid inclusions in minerals from agpaitic nepheline syenites and hydrothermal veins in the Ilímaussaq complex and in similar agpaitic complexes on the Kola Peninsula, Russia, are dominated by hydrocarbon gases (predominantly methane) and hydrogen. Such volatile compositions differ considerably from those of most other igneous rocks and their formation and entrapment in minerals reflects low oxygen fugacities and a wide range of crystallisation temperatures extending to a low-temperature solidus. Their composition reflects initial low carbon contents and high water contents of the magma resulting in the exsolution of a waterrich CO2–H2O dominated vapour phase. Fractionation of chlorides into the vapour phase results in high salinities and the subsequent development of a heterogeneous vapour phase with a highly saline aqueous-rich fraction and a methane-dominated fraction, with preferential entrapment of the latter, possibly due to different wetting characteristics. The light stable isotope compositions support an abiogenic origin for the hydrocarbons in agpaitic nepheline syenite complexes.

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