Temperature-dependent adjustment of the thermal stability of photosystem II in vivo: possible involvement of xanthophyll-cycle pigments

Planta ◽  
1996 ◽  
Vol 198 (3) ◽  
pp. 324-333 ◽  
Author(s):  
Michel Havaux ◽  
Florence Tardy
Keyword(s):  
Thermal Stability ◽  
Photosystem Ii ◽  
Xanthophyll Cycle ◽  
Temperature Dependent ◽  
Xanthophyll Cycle Pigments ◽  
Thermal Stability Of

scholarly journals Phase transition and thermal stability of epitaxial PtSe2 nanolayer on Pt(111)

RSC Advances ◽  
2020 ◽  
Vol 10 (51) ◽  
pp. 30934-30943 ◽  
Author(s):  
Yongfeng Tong ◽  
Meryem Bouaziz ◽  
Hamid Oughaddou ◽  
Hanna Enriquez ◽  
Karine Chaouchi ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Chemical Deposition ◽  
Deposition Method ◽  
Temperature Dependent ◽  
Chemical Deposition Method ◽  
Thermal Stability Of

LEED, STM and XPS techniques were used to systematically study a temperature-dependent phase transition on a PtSe2 film grown on the surface of Pt(111) by a chemical deposition method.

Thermal stability of photosystem II of Arabidopsis mutants deficient in fatty acid desaturation

1994 ◽  
Vol 22 (3) ◽  
pp. 379S-379S
Author(s):  
NELLY M. TSVETKOVA ◽  
EMELIA APOSTOLOVA ◽  
W. PATRICK WILLIAMS ◽  
PETER J. QUINN
Keyword(s):  
Thermal Stability ◽  
Fatty Acid ◽  
Photosystem Ii ◽  
Fatty Acid Desaturation ◽  
Arabidopsis Mutants ◽  
Thermal Stability Of

scholarly journals Improved Insights into Protein Thermal Stability: From the Molecular to the Structurome Scale

2016 ◽  
Author(s):  
Fabrizio Pucci ◽  
Marianne Rooman
Keyword(s):  
Thermal Stability ◽  
Amino Acid ◽  
Protein Stability ◽  
Large Scale ◽  
Molecular Level ◽  
Temperature Dependent ◽  
Natural Evolution ◽  
Multi Scale ◽  
Large Scale Analysis ◽  
Thermal Stability Of

AbstractDespite the intense efforts of the last decades to understand the thermal stability of proteins, the mechanisms responsible for its modulation still remain debated. In this investigation, we tackle this issue by showing how a multi-scale perspective can yield new insights. With the help of temperature-dependent statistical potentials, we analyzed some amino acid interactions at the molecular level, which are suggested to be relevant for the enhancement of thermal resistance. We then investigated the thermal stability at the protein level by quantifying its modification upon amino acid substitutions. Finally, a large scale analysis of protein stability - at the structurome level - contributed to the clarification of the relation between stability and natural evolution, thereby showing that the mutational profile of thermostable and mesostable proteins differ. Some final considerations on how the multi-scale approach could help unraveling the protein stability mechanisms are briefly discussed.

Effects of glycine betaine and glycerophosphocholine on thermal stability of ribonuclease

1998 ◽  
Vol 274 (4) ◽  
pp. F762-F765 ◽  
Author(s):  
Maurice B. Burg ◽  
Eugenia M. Peters
Keyword(s):  
Thermal Stability ◽  
Tissue Culture ◽  
Glycine Betaine ◽  
Metabolic Cost ◽  
Rnase A ◽  
Renal Cells ◽  
And Function ◽  
Thermal Stability Of

Urea in renal medullas is sufficiently high to perturb macromolecules, yet the cells survive and function. The counteracting osmolytes hypothesis holds that methylamines, such as glycine betaine (betaine) and glycerophosphocholine (GPC) in renal medullas, stabilize macromolecules and oppose the effects of urea. Although betaine counteracts effects of urea on macromolecules in vitro and protects renal cells from urea in tissue culture, renal cells accumulate GPC rather than betaine in response to high urea both in vivo and in tissue culture. A proposed explanation is that GPC counteracts urea more effectively than betaine. However, we previously found GPC slightly less effective than betaine in counteracting inhibition of pyruvate kinase activity by urea. To test another macromolecule, we now compare GPC and betaine in counteracting reduction of the thermal stability of RNase A by urea. We find that urea decreases the thermal transition temperature and that betaine and GPC increase it, counteracting urea approximately equally. Therefore, the preference for GPC in response to high urea presumably has some other basis, such as a lower metabolic cost of GPC accumulation.

A comparative analysis of the evolutionary patterning and mechanistic bases of lactate dehydrogenase thermal stability in porcelain crabs, genus Petrolisthes

2001 ◽  
Vol 204 (4) ◽  
pp. 767-776
Author(s):  
J.H. Stillman ◽  
G.N. Somero
Keyword(s):  
Thermal Stability ◽  
Comparative Analysis ◽  
Lactate Dehydrogenase ◽  
Protein Interactions ◽  
Kinetic Properties ◽  
Post Translational Modification ◽  
Extrinsic Factors ◽  
Thermal Stability Of ◽  
Interspecific Diversity

The kinetic properties of orthologous homologs (orthologs) of enzymes are typically correlated with environmental temperatures in species adapted to different thermal regimes, but correlations between adaptation temperature and enzyme thermal stability are less clear. Although the thermal stability of a protein is related chiefly to its primary structure (including post-translational modification), thermal stability can also be altered by extrinsic factors present in the intracellular milieu. Here, we present a comparative analysis of the thermal stability of lactate dehydrogenase (LDH) orthologs from 22 congeneric species of porcelain crab (genera Petrolisthes and Allopetrolisthes) from a broad range of thermal habitats. Interspecific diversity of LDH stability is high: temperatures required for a 50 % loss of activity in 10 min ranged from 65 to 75.5 degrees C, corresponding to half-lives of less than 1 min to more than 3 h at 70 degrees C. Although stability is positively correlated with maximal habitat temperature in some sister taxa, phylogenetic comparative analysis incorporating all 22 species does not indicate that the interspecific diversity of LDH stability represents an adaptive response to current thermal habitats. Examination of the mechanistic bases of LDH stabilization indicates that differences in stability are related both to properties of the LDH molecule itself (intrinsic stability) and to the effects of extrinsic protein(s). Intrinsic differences were shown by the unfolding of structure during heating, as measured by circular dichroism spectroscopy. Stabilizing effects of extrinsic proteins are implied by the results of cellular fractionation experiments that removed low-molecular-mass solutes and proteins from the muscle homogenates. We conclude that the overall structural stability and functional properties of proteins can evolve independently and that in vivo protein-protein interactions can provide another means to regulate protein stability selectively.

NONSPHEROCYTIC CONGENITAL HEMOLYTIC ANEMIA DUE TO A NEW G-6-PD VARIANT: G-6-PD ALHAMBRA

PEDIATRICS ◽  
1970 ◽  
Vol 45 (2) ◽  
pp. 230-235
Author(s):  
Ernest Beutler ◽  
Robert Rosen
Keyword(s):  
Thermal Stability ◽  
Hemolytic Anemia ◽  
Red Cells ◽  
Essentially Normal ◽  
New Variant ◽  
Thermal Stability Of ◽  
Congenital Hemolytic Anemia

An 11-year-old boy was first known to have a hemolytic episode at the age of 8 years, and a diagnosis of nonspherocytic congenital hemolytic anemia due to G-6-PD deficiency was made soon after the hemolytic episode. The red cells of the patient contained a level of G-6-PD activity approximating 10 to 25% of normal. The residual enzyme was partly purified and characterized. It proved to be electrophoretically slow, and was kinetically essentially normal. The thermal stability of the enzyme was reduced and its stability in vivo was markedly diminished. This enzyme represents a new variant which has been named G-6-PD Alhambra.

scholarly journals Allosteric regulation of the light-harvesting system of photosystem II

2000 ◽  
Vol 355 (1402) ◽  
pp. 1361-1370 ◽  
Author(s):  
Peter Horton ◽  
Alexander V. Ruban ◽  
Mark Wentworth
Keyword(s):  
Photosystem Ii ◽  
Xanthophyll Cycle ◽  
Light Harvesting ◽  
Allosteric Regulation ◽  
Photochemical Quenching ◽  
Protein Subunit ◽  
Ps Ii ◽  
Non Photochemical Quenching

Non–photochemical quenching of chlorophyll fluorescence (NPQ) is symptomatic of the regulation of energy dissipation by the light–harvesting antenna of photosystem II (PS II). The kinetics of NPQ in both leaves and isolated chloroplasts are determined by the transthylakoid ΔpH and the de–epoxidation state of the xanthophyll cycle. In order to understand the mechanism and regulation of NPQ we have adopted the approaches commonly used in the study of enzyme–catalysed reactions. Steady–state measurements suggest allosteric regulation of NPQ, involving control by the xanthophyll cycle carotenoids of a protonationdependent conformational change that transforms the PS II antenna from an unquenched to a quenched state. The features of this model were confirmed using isolated light–harvesting proteins. Analysis of the rate of induction of quenching both in vitro and in vivo indicated a bimolecular second–order reaction; it is suggested that quenching arises from the reaction between two fluorescent domains, possibly within a single protein subunit. A universal model for this transition is presented based on simple thermodynamic principles governing reaction kinetics.

Thermal stability of phases in a NiCoCrAlY coating alloy

2008 ◽  
Vol 23 (8) ◽  
pp. 2264-2274 ◽  
Author(s):  
J.J. Liang ◽  
H. Wei ◽  
G.C. Hou ◽  
Q. Zheng ◽  
X.F. Sun ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Temperature Dependence ◽  
Experimental Observation ◽  
Thermodynamic Modeling ◽  
Thermodynamic Data ◽  
Reasonable Agreement ◽  
Temperature Dependent ◽  
Thermal Stabilities ◽  
Thermal Stability Of ◽  
Coating Alloy

The temperature dependence of the thermal stability in a NiCoCrAlY coating alloy was examined by experimental observation and thermodynamic modeling in the 400–1200 °C temperature range. The results indicated that the thermal stabilities of primary β–NiAl, β–NiAl/α–Cr eutectic, and γ–Ni were slightly temperature dependent, but those of γ′–Ni3Al, σ–(Cr,Co,Ni), and α–Cr were strongly temperature dependent in the annealed NiCoCrAlY specimens. The temperature dependence of the thermal stabilities among γ′–Ni3Al, σ–(Cr,Co,Ni), and α–Cr might be ascribed to the σ → α transformation at ∼1100 °C and the γ′ → γ transformation at ∼800 °C. Further, using Thermocalc associated with TTNi7 database, thermodynamic equilibria were calculated. The modeling results were compared with the experimental results and found to be in reasonable agreement with the experimental observations of β–NiAl, σ–(Cr,Co,Ni), and γ′–Ni3Al. Some deviations observed are discussed in the light of both limited availability of thermodynamic data and experimental problems.

Enhancing the thermal stability of a single-chain Fv fragment by in vivo global fluorination of the proline residues

2011 ◽  
Vol 7 (1) ◽  
pp. 258-265 ◽  
Author(s):  
Selvakumar Edwardraja ◽  
Sokalingam Sriram ◽  
Raghunathan Govindan ◽  
Nediljko Budisa ◽  
Sun-Gu Lee
Keyword(s):  
Thermal Stability ◽  
Single Chain ◽  
Single Chain Fv ◽  
Single Chain Fv Fragment ◽  
Thermal Stability Of
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