ChemInform Abstract: Evidence for Substrate Activation of Copper-Catalyzed Intradiol Cleavage in Pyrocatechols

ChemInform ◽  
2010 ◽  
Vol 26 (1) ◽  
pp. no-no
Author(s):  
G. SPEIER ◽  
Z. TYEKLAR ◽  
L. II SZABO ◽  
P. TOTH ◽  
C. G. PIERPONT ◽  
...  
Keyword(s):  
Substrate Activation ◽  
Intradiol Cleavage

Evidences for Substrate Activation of Copper Catalyzed Intradiol Cleavage in Catechols

1993 ◽  
pp. 423-436 ◽  
Author(s):  
Gábor Speier ◽  
Zoltán Tyeklár ◽  
Lajos Szabó ◽  
Péter Tóth ◽  
Cortland G. Pierpont ◽  
...  
Keyword(s):  
Substrate Activation ◽  
Intradiol Cleavage

Generation Of Factor XII-Dependent Plasminogen Activator Activity In Human Plasma Measured With A Fluorogenic Substrate

1981 ◽  
Author(s):  
G Dooijewaard ◽  
C Kluft
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Minor Role ◽  
Factor Xii ◽  
Dextran Sulphate ◽  
Fluorogenic Substrate ◽  
A Value ◽  
Substrate Activation ◽  
Factor Xiia ◽  
A Minor

A rapid fluorometric assay for measurement of amidolytic activity in human plasma was developed, using the plasminogen activator sensitive synthetic substrate t-BOC-L-valyl--glycyl-L-arginine-β-naphthylamide. The plasma is diluted in a reaction cuvet containing 0.050 M Tris HC1 buffer (pH 8.0) and 150 μM substrate. Activation of plasminogen proactivator(s) is initiated at 37°C by the addition of 10 μg dextran sulphate (MW 500,000)/ml. The concentration of β-naphthyl- amide released is recorded fluorometrically as a function of time. The slope of this curve at any time t is proportional to the concentration of activator. Thus, in a single assay, the entire time-dependent profile of activation and subsequent inhibition is monitored; this provides 1. a value for an optimum plasminogen activator content in the plasma, and 2. the time it takes to reach the optimum. The plot of optimum activator content against μl of plasma added is linear for dilutions more than 100-fold, suggesting that under these conditions the optimum content approaches the content of proactivator(s) originally present.The activator content measured predominantly consists of contributions of a factor XII-dependent process since 1. without dextran sulphate or with plasmas deficient in factor XII or prekallikrein no activity could be generated, and 2. plots of optimum activator content against dextran sulphate concentration show sigmoidal-shaped saturation curves as found previously for the kallikrein generation in human plasma. Contributions of factor XIIa and kallikrein only partly account for the content measured and studies with plasmas deficient in factor XI point to a minor role for this factor, if any. Further identification of the activator (s) involved is in progress.

scholarly journals Cell Behavior of Primary Fibroblasts and Osteoblasts on Plasma-Treated Fluorinated Polymer Coated with Honeycomb Polystyrene

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 889
Author(s):  
Klára Fajstavrová ◽  
Silvie Rimpelová ◽  
Dominik Fajstavr ◽  
Václav Švorčík ◽  
Petr Slepička
Keyword(s):  
Chemical Properties ◽  
Plasma Exposure ◽  
Research Teams ◽  
Polymer Substrates ◽  
Substrate Activation ◽  
Physico Chemical ◽  
Polystyrene Solution ◽  
Primary Fibroblasts ◽  
Positive Effect ◽  
Cell Adhesion And Proliferation

The development of new biocompatible polymer substrates is still of interest to many research teams. We aimed to combine a plasma treatment of fluorinated ethylene propylene (FEP) substrate with a technique of improved phase separation. Plasma exposure served for substrate activation and modification of surface properties, such as roughness, chemistry, and wettability. The treated FEP substrate was applied for the growth of a honeycomb-like pattern from polystyrene solution. The properties of the pattern strongly depended on the primary plasma exposure of the FEP substrate. The physico-chemical properties such as changes of the surface chemistry, wettability, and morphology of the prepared pattern were determined. The cell response of primary fibroblasts and osteoblasts was studied on a honeycomb pattern. The prepared honeycomb-like pattern from polystyrene showed an increase in cell viability and a positive effect on cell adhesion and proliferation for both primary fibroblasts and osteoblasts.

scholarly journals Molecular Mechanism of Allosteric Substrate Activation in a Thiamine Diphosphate-dependent Decarboxylase

2007 ◽  
Vol 282 (48) ◽  
pp. 35269-35278 ◽  
Author(s):  
Wim Versées ◽  
Stijn Spaepen ◽  
Martin D. H. Wood ◽  
Finian J. Leeper ◽  
Jos Vanderleyden ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Thiamine Diphosphate ◽  
Substrate Activation

scholarly journals New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

2016 ◽  
Vol 12 ◽  
pp. 2834-2848 ◽  
Author(s):  
Pavel Nagorny ◽  
Zhankui Sun
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Recent Progress ◽  
Halogen Bonds ◽  
Hydrogen Bond Donor ◽  
New Approaches ◽  
Substrate Activation ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Hydrogen Bond Donors

Hydrogen bond donor catalysis represents a rapidly growing subfield of organocatalysis. While traditional hydrogen bond donors containing N–H and O–H moieties have been effectively used for electrophile activation, activation based on other types of non-covalent interactions is less common. This mini review highlights recent progress in developing and exploring new organic catalysts for electrophile activation through the formation of C–H hydrogen bonds and C–X halogen bonds.

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