Slow Photo-Cross-Linking Kinetics of Benzophenone-Labeled Voltage Sensors of Ion Channels†

Biochemistry ◽  
2001 ◽  
Vol 40 (35) ◽  
pp. 10707-10716 ◽  
Author(s):  
Shinghua Ding ◽  
Richard Horn
Keyword(s):  
Ion Channels ◽  
Cross Linking ◽  
Voltage Sensors ◽  
Kinetics Of

Extraction of Auditory Information by Modulation of Neuronal Ion Channels

2018 ◽  
pp. 272-300
Author(s):  
Leonard K. Kaczmarek
Keyword(s):  
Ion Channels ◽  
Neuronal Firing ◽  
Auditory Information ◽  
Auditory Neurons ◽  
Complex Sound ◽  
Medial Nucleus ◽  
Rapid Changes ◽  
Genes Encoding ◽  
Kinetics Of ◽  
Trapezoid Body

All neurons express a subset of over seventy genes encoding potassium channel subunits. These channels have been studied in auditory neurons, particularly in the medial nucleus of the trapezoid body. The amplitude and kinetics of various channels in these neurons can be modified by the auditory environment. It has been suggested that such modulation is an adaptation of neuronal firing patterns to specific patterns of auditory inputs. Alternatively, such modulation may allow a group of neurons, all expressing the same set of channels, to represent a variety of responses to the same pattern of incoming stimuli. Such diversity would ensure that a small number of genetically identical neurons could capture and encode many aspects of complex sound, including rapid changes in timing and amplitude. This review covers the modulation of ion channels in the medial nucleus of the trapezoid body and how it may maximize the extraction of auditory information.All neurons express a subset of over seventy genes encoding potassium channel subunits. These channels have been studied in auditory neurons, particularly in the medial nucleus of the trapezoid body. The amplitude and kinetics of various channels in these neurons can be modified by the auditory environment. It has been suggested that such modulation is an adaptation of neuronal firing patterns to specific patterns of auditory inputs. Alternatively, such modulation may allow a group of neurons, all expressing the same set of channels, to represent a variety of responses to the same pattern of incoming stimuli. Such diversity would ensure that a small number of genetically identical neurons could capture and encode many aspects of complex sound, including rapid changes in timing and amplitude. This review covers the modulation of ion channels in the medial nucleus of the trapezoid body and how it may maximize the extraction of auditory information.

scholarly journals Kinetics of Cross-Linking of Peptidoglycan in Bacillus megaterium

1974 ◽  
Vol 249 (8) ◽  
pp. 2478-2482
Author(s):  
William D. Fordham ◽  
Charles Gilvarg
Keyword(s):  
Bacillus Megaterium ◽  
Cross Linking ◽  
Kinetics Of

scholarly journals Viscometric analysis of the gelation of Acanthamoeba extracts and purification of two gelation factors.

1980 ◽  
Vol 85 (2) ◽  
pp. 414-428 ◽  
Author(s):  
S D MacLean-Fletcher ◽  
T D Pollard
Keyword(s):  
Crude Extract ◽  
Cross Linking ◽  
Cross Link ◽  
Gelation Process ◽  
Optimum Ph ◽  
Kinetics Of ◽  
Low Shear

We have studied the kinetics of the gelation process that occurs upon warming cold extracts of Acanthamoeba using a low-shear falling ball assay. We find that the reaction has at least two steps, requires 0.5 mM ATP and 1.5 mM MgCl2, and is inhibited by micromolar Ca++. The optimum pH is 7.0 and temperature, 25 degrees-30 degrees C. The rate of the reaction is increased by cold preincubation with both MgCl2 and ATP. Nonhydrolyzable analogues of ATP will not substitute for ATP either in this "potentiation reaction" or in the gelation process. Either of two purified or any one of four partially purified Acanthamoeba proteins will cross-link purified actin to form a gel, but none can account for the dependence of the reaction in the crude extract on Mg-ATP or its regulation by Ca++. This suggests that the extract contains, in addition to actin-cross-linking proteins, factors dependent on Mg-ATP and Ca++ that regulate the gelation process.

scholarly journals Single-sided NMR for the measurement of the degree of cross-linking and curing

2018 ◽  
Vol 7 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Norbert Halmen ◽  
Christoph Kugler ◽  
Eduard Kraus ◽  
Benjamin Baudrit ◽  
Thomas Hochrein ◽  
...  
Keyword(s):  
Relaxation Times ◽  
Curing Kinetics ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
First Results ◽  
Non Destructive ◽  
Kinetics Of ◽  
Good Agreement

Abstract. The degree of cross-linking and curing is one of the most important values concerning the quality of cross-linked polyethylene (PE-X) and the functionality of adhesives and resin-based components. Up to now, the measurement of this property has mostly been time-consuming and usually destructive. Within the shown work the feasibility of single-sided nuclear magnetic resonance (NMR) for the non-destructive determination of the degree of cross-linking and curing as process monitoring was investigated. First results indicate the possibility of distinguishing between PE-X samples with different degrees of cross-linking. The homogeneity of the samples and the curing kinetics of adhesives can also be monitored. The measurements show good agreement with reference tests (wet chemical analysis, differential scanning calorimetry, dielectric analysis). Furthermore, the influence of sample temperature on the characteristic relaxation times can be observed.

scholarly journals Improvement of recovered activity and stability of the Aspergillus oryzae β-galactosidase immobilized on duolite A568 by combination of immobilization methods

2017 ◽  
Vol 23 (4) ◽  
pp. 495-506 ◽  
Author(s):  
Larissa Falleiros ◽  
Bruna Cabral ◽  
Janaína Fischer ◽  
Carla Guidini ◽  
Vicelma Cardoso ◽  
...  
Keyword(s):  
Activation Energy ◽  
Aspergillus Oryzae ◽  
Physical Adsorption ◽  
Cross Linking ◽  
Thermal Deactivation ◽  
Order Model ◽  
First Order ◽  
Immobilized Biocatalyst ◽  
The Stability ◽  
Kinetics Of

The immobilization and stabilization of Aspergillus oryzae ?-galactosidase on Duolite??A568 was achieved using a combination of physical adsorption, incubation step in buffer at pH 9.0 and cross-linking with glutaraldehyde and in this sequence promoted a 44% increase in enzymatic activity as compared with the biocatalyst obtained after a two-step immobilization process (adsorption and cross-linking). The stability of the biocatalyst obtained by three-step immobilization process (adsorption, incubation in buffer at pH 9.0 and cross-linking) was higher than that obtained by two-steps (adsorption and cross-linking) and for free enzyme in relation to pH, storage and reusability. The immobilized biocatalyst was characterized with respect to thermal stability in the range 55-65 ?C. The kinetics of thermal deactivation was well described by the first-order model, which resulted in the immobilized biocatalyst activation energy of thermal deactivation of 71.03 kcal/mol and 5.48 h half-life at 55.0 ?C.

A comparative study on the effect of higher acrylate on cross-linkable PMMA used as environment friendly latexes

2020 ◽  
Vol 32 (2) ◽  
pp. 135-141
Author(s):  
Sweta Shukla
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Butyl Methacrylate ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
Environment Friendly ◽  
Glycol Diacrylate ◽  
Poly Propylene ◽  
Kinetics Of ◽  
Scanning Electron

The kinetics of emulsion polymerization of monomers methyl methacrylate (MMA)/ n-butyl methacrylate (BMA) was studied to investigate the effect of cross-linkable monomer poly(propylene glycol diacrylate) (PPGDA). The results showed that by the incorporation of PPGDA rate constant of reaction decreased. Fourier transform infrared spectroscopy and scanning electron microscope were used to characterize the synthesized polymers. The thermal analysis of samples was done by differential scanning calorimetry, and the results were compared by the previous studies with MMA/ n-butyl acrylate (BA) and MMA/2-ethylhexyl acrylate (EHA). The glass transition temperature ( T g) values show that the latexes prepared using BA and EHA as comonomer was suitable for binder purpose, but in the present study the T g is not suitable in case of BMA as higher acrylate comonomer. That may be due to more cross-linking in MMA-BMA-PPGDA. The results conclude that the BA and EHA can be used as the binder, but the use of BMA is limited for the binder in coating applications.

Kinetics of Free-Radical Cross-Linking Polymerization: Comparative Experimental and Numerical Study

2013 ◽  
Vol 46 (15) ◽  
pp. 5831-5841 ◽  
Author(s):  
Marco Lattuada ◽  
Emanuela Del Gado ◽  
Tiziana Abete ◽  
Lucilla de Arcangelis ◽  
Stefano Lazzari ◽  
...  
Keyword(s):  
Free Radical ◽  
Numerical Study ◽  
Cross Linking ◽  
Kinetics Of

Conversation between Voltage Sensors and Gates of Ion Channels

Biochemistry ◽  
2000 ◽  
Vol 39 (51) ◽  
pp. 15653-15658 ◽  
Author(s):  
Richard Horn
Keyword(s):  
Ion Channels ◽  
Voltage Sensors
Sign in / Sign up

Export Citation Format

Share Document