Localization of the xanthophyll-cycle enzyme violaxanthin de-epoxidase within the thylakoid lumen and abolition of its mobility by a (light-dependent) pH decrease

Planta ◽  
1994 ◽  
Vol 192 (4) ◽  
Author(s):  
A. Hager ◽  
K. Holocher
Keyword(s):  
Xanthophyll Cycle ◽  
Thylakoid Lumen ◽  
Cycle Enzyme ◽  
Ph Decrease

Influence of ascorbate and pH on the activity of the diatom xanthophyll cycle-enzyme diadinoxanthin de-epoxidase

2006 ◽  
Vol 126 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Irina Grouneva ◽  
Torsten Jakob ◽  
Christian Wilhelm ◽  
Reimund Goss
Keyword(s):  
Xanthophyll Cycle ◽  
Cycle Enzyme

Violaxanthin De-Epoxidase, the Xanthophyll Cycle Enzyme, Requires Lipid Inverted Hexagonal Structures for Its Activity†

Biochemistry ◽  
2004 ◽  
Vol 43 (15) ◽  
pp. 4417-4420 ◽  
Author(s):  
Dariusz Latowski ◽  
Hans-Erik Åkerlund ◽  
Kazimierz Strzałka
Keyword(s):  
Xanthophyll Cycle ◽  
Cycle Enzyme

scholarly journals Kinetics of violaxanthin de-epoxidation by violaxanthin de-epoxidase, a xanthophyll cycle enzyme, is regulated by membrane fluidity in model lipid bilayers

2002 ◽  
Vol 269 (18) ◽  
pp. 4656-4665 ◽  
Author(s):  
Dariusz Latowski ◽  
Jerzy Kruk ◽  
Kvetoslava Burda ◽  
Marta Skrzynecka-Jaskier ◽  
Anna Kostecka-Gugała ◽  
...  
Keyword(s):  
Membrane Fluidity ◽  
Lipid Bilayers ◽  
Xanthophyll Cycle ◽  
Cycle Enzyme ◽  
Kinetics Of

Using seafood waste as sludge conditioners

2001 ◽  
Vol 44 (10) ◽  
pp. 301-307 ◽  
Author(s):  
D.Y. Lee ◽  
S.R. Jing ◽  
Y.F. Lin
Keyword(s):  
Ferric Chloride ◽  
Specific Resistance ◽  
Oyster Shell ◽  
Particle Sizes ◽  
Sludge Dewatering ◽  
Insignificant Effect ◽  
Shrimp Shell ◽  
Ph Decrease ◽  
Shell Particles ◽  
Bone Particles

In this study, three kinds of seafood wastes (shrimp shell particles, oyster shell particles, and internal bone particles of squid) were added to dewatered sludge preconditioned with chemical conditioner (alum or ferric chloride). The specific resistance of sludge dewatering was calculated to evaluate the effectiveness of sludge dewatering. The result showed that adding chemical conditioners alone caused noticeable pH decrease and resulted in a conditioned sludge with poor filterability. The addition of oyster shell or internal bone of squid to chemically preconditioned sludge efficiently improved sludge dewatering. This result was possibly due to both the availability of alkaline and the function as skeleton builder provided by these two waste solids. Particle sizes (0.59-2.0 mm) of oyster shell and internal bone of squid were found to have insignificant effect on sludge dewatering.

Effect of Short-Term Temperature Increase on the Performance of a Mesophilic UASB Reactor

1990 ◽  
Vol 22 (9) ◽  
pp. 183-190 ◽  
Author(s):  
J. B. van Lier ◽  
J. Rintala ◽  
J. L. Sanz Martin ◽  
G. Lettinga
Keyword(s):  
Sharp Decrease ◽  
Methanogenic Bacteria ◽  
Decay Rates ◽  
Uasb Reactor ◽  
Short Term ◽  
Retention Capacity ◽  
Temperature Shock ◽  
Biomass Retention ◽  
Propionate Oxidation ◽  
Ph Decrease

A study was carried out to assess the effects of short-term temperature increments on the treatment efficiency and methane production of UASB reactors at a working temperature of 37-39°C. Two different substrates were used to determine the effects on the several bacterial groups involved in the digestion process. One reactor was fed with defined synthetic acidified wastewater the other with unacidified wastewaler from a distillery process. Shocks of 5-24 hrs were applied at temperatures in the range of 45 to 61°C. Up to 45°C no detrimental effects were noticeable. Higher temperatures led to a sharp decrease of the activity of the different microbial populations as a result of elevated decay rates. Propionate oxidation turned out to be the most sensitive for temperature increments, whereas the acidogenic bacteria were least affected. Temperature shocks of 55 and 61°C led to a decrease of 50% of the overall efficiency after 10 and 3 hrs, respectively. By means of batch experiments decay rates of 0.44 and > 10 hr −1 of the methanogenic bacteria were estimated at 55 and 65°C respectively. As temporary inactivation of the mesophilic bacteria during a temperature shock was found to be unlikely, reactor recovery is dependent on the bacterial growth and the biomass retention capacity of the reactor. When unacidified wastewater is treated, a pH decrease has to be considered during a temperature shock.

PBA increases CFTR expression but at high doses inhibits Cl−secretion in Calu-3 airway epithelial cells

1999 ◽  
Vol 277 (4) ◽  
pp. L700-L708 ◽  
Author(s):  
Johannes Loffing ◽  
Bryan D. Moyer ◽  
Donna Reynolds ◽  
Bruce A. Stanton
Keyword(s):  
Protein Expression ◽  
Apical Membrane ◽  
Basolateral Membrane ◽  
Airway Epithelial Cells ◽  
Cell Phenotype ◽  
Apical Plasma Membrane ◽  
Airway Epithelial ◽  
High Concentration ◽  
Cycle Enzyme ◽  
Cf Transmembrane Conductance Regulator

Sodium 4-phenylbutyrate (PBA), a short-chain fatty acid, has been approved to treat patients with urea cycle enzyme deficiencies and is being evaluated in the management of sickle cell disease, thalassemia, cancer, and cystic fibrosis (CF). Because relatively little is known about the effects of PBA on the expression and function of the wild-type CF transmembrane conductance regulator (wt CFTR), the goal of this study was to examine the effects of PBA and related compounds on wt CFTR-mediated Cl−secretion. To this end, we studied Calu-3 cells, a human airway cell line that expresses endogenous wt CFTR and has a serous cell phenotype. We report that chronic treatment of Calu-3 cells with a high concentration (5 mM) of PBA, sodium butyrate, or sodium valproate but not of sodium acetate reduced basal and 8-(4-chlorophenylthio)-cAMP-stimulated Cl−secretion. Paradoxically, PBA enhanced CFTR protein expression 6- to 10-fold and increased the intensity of CFTR staining in the apical plasma membrane. PBA also increased protein expression of Na+-K+-ATPase. PBA reduced CFTR Cl−currents across the apical membrane but had no effect on Na+-K+-ATPase activity in the basolateral membrane. Thus a high concentration of PBA (5 mM) reduces Cl−secretion by inhibiting CFTR Cl−currents across the apical membrane. In contrast, lower therapeutic concentrations of PBA (0.05–2 mM) had no effect on cAMP-stimulated Cl−secretion across Calu-3 cells. We conclude that PBA concentrations in the therapeutic range are unlikely to have a negative effect on Cl−secretion. However, concentrations >5 mM might reduce transepithelial Cl−secretion by serous cells in submucosal glands in individuals expressing wt CFTR.

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