The Influence of Sodium-Dodecylsulfate on the Stability of Cyanobacterial Photosystem-1 Pigment-Protein Complexes

1992 ◽  
Vol 140 (6) ◽  
pp. 667-672
Author(s):  
Jan Otcovský ◽  
Jiří Hladík ◽  
Danuše Sofrová
Keyword(s):  
Protein Complexes ◽  
Sodium Dodecylsulfate ◽  
Photosystem 1 ◽  
Pigment Protein Complexes ◽  
The Stability

scholarly journals Effect of Oxygen on Translation and Posttranslational Steps in Expression of Photosynthesis Genes inRhodobacter capsulatus

1998 ◽  
Vol 180 (15) ◽  
pp. 3983-3987 ◽  
Author(s):  
Markus Hebermehl ◽  
Gabriele Klug
Keyword(s):  
Gene Expression ◽  
Oxygen Tension ◽  
Rhodobacter Capsulatus ◽  
Protein Complexes ◽  
Photosynthetic Apparatus ◽  
Regulatory Effect ◽  
Pigment Protein Complexes ◽  
Photosynthesis Genes ◽  
The Stability ◽  
Effect Of Oxygen

ABSTRACT The formation of the photosynthetic apparatus in Rhodobacter capsulatus is regulated by oxygen tension. Previous studies have shown a regulatory effect of oxygen on the transcription of photosynthesis genes and on the stability of certain mRNA segments. Here we show that oxygen affects puf and pucgene expression posttranslationally and that this regulation depends on the presence of bacteriochlorophyll. Our data suggest that this posttranslational effect of oxygen on puf andpuc expression is due to the primary effect of oxygen on bacteriochlorophyll synthesis or assembly of pigment protein complexes. Oxygen does not affect the rates of translation ofpuf-encoded proteins.

scholarly journals Antioxidant effects of carotenoids in a model pigment-protein complex.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Joanna Fiedor ◽  
Aleksandra Sulikowska ◽  
Aleksandra Orzechowska ◽  
Leszek Fiedor ◽  
Květoslava Burda
Keyword(s):  
Protein Complexes ◽  
Photosynthetic Pigment ◽  
Chemical Oxidation ◽  
Antioxidant Effect ◽  
Absorption And Fluorescence Spectroscopy ◽  
Pigment Protein Complexes ◽  
Photosynthetic Complexes ◽  
The Stability ◽  
Pigment Protein Complex ◽  
Antioxidant Effects

The effect of carotenoids on stability of model photosynthetic pigment-protein complexes subjected to chemical oxidation with hydrogen peroxide or potassium ferricyanide was investigated. The oxidation of carotenoid-less and carotenoid-containing complexes was conducted in the presence or absence of ascorbic acid. The progress of the reactions was monitored by use of absorption and fluorescence spectroscopy. Our results show that carotenoids may significantly enhance the stability of photosynthetic complexes against oxidation and their protective (antioxidant) effect depends on the type of the oxidant.

scholarly journals Rational thermostabilisation of four-helix bundle dimeric de novo proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shin Irumagawa ◽  
Kaito Kobayashi ◽  
Yutaka Saito ◽  
Takeshi Miyata ◽  
Mitsuo Umetsu ◽  
...  
Keyword(s):  
Protein Design ◽  
De Novo ◽  
Protein Complexes ◽  
Salt Bridge ◽  
Dynamics Simulation ◽  
Saturation Mutagenesis ◽  
Helix Bundle ◽  
Stable Mutant ◽  
Four Helix Bundle ◽  
The Stability

AbstractThe stability of proteins is an important factor for industrial and medical applications. Improving protein stability is one of the main subjects in protein engineering. In a previous study, we improved the stability of a four-helix bundle dimeric de novo protein (WA20) by five mutations. The stabilised mutant (H26L/G28S/N34L/V71L/E78L, SUWA) showed an extremely high denaturation midpoint temperature (Tm). Although SUWA is a remarkably hyperstable protein, in protein design and engineering, it is an attractive challenge to rationally explore more stable mutants. In this study, we predicted stabilising mutations of WA20 by in silico saturation mutagenesis and molecular dynamics simulation, and experimentally confirmed three stabilising mutations of WA20 (N22A, N22E, and H86K). The stability of a double mutant (N22A/H86K, rationally optimised WA20, ROWA) was greatly improved compared with WA20 (ΔTm = 10.6 °C). The model structures suggested that N22A enhances the stability of the α-helices and N22E and H86K contribute to salt-bridge formation for protein stabilisation. These mutations were also added to SUWA and improved its Tm. Remarkably, the most stable mutant of SUWA (N22E/H86K, rationally optimised SUWA, ROSA) showed the highest Tm (129.0 °C). These new thermostable mutants will be useful as a component of protein nanobuilding blocks to construct supramolecular protein complexes.

scholarly journals The influence of sugar–protein complexes on the thermostability of C-reactive protein (CRP)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreea Lorena Mateescu ◽  
Nicolae-Bogdan Mincu ◽  
Silvana Vasilca ◽  
Roxana Apetrei ◽  
Diana Stan ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
Protein Complexes ◽  
C Reactive Protein ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Reactive Protein ◽  
In Vitro Diagnostic ◽  
The Stability ◽  
Positive Controls

AbstractThe purpose of the present study was to evaluate de influence of protein–sugar complexation on the stability and functionality of C-reactive protein, after exposure to constant high temperatures, in order to develop highly stable positive controls for in-vitro diagnostic tests. C-reactive protein is a plasmatic protein used as a biomarker for the diagnosis of a series of health problems such as ulcerative colitis, cardiovascular diseases, metabolic syndrome, due to its essential role in the evolution of chronic inflammation. The sugar–protein interaction was investigated using steady state and time resolved fluorescence. The results revealed that there are more than two classes of tryptophan, with different degree of accessibility for the quencher molecule. Our study also revealed that sugar–protein complexes have superior thermostability, especially after gamma irradiation at 2 kGy, the protein being stable and functional even after 22 days exposure to 40 °C.

Carotenoidless pigment-protein complexes of the sulfur photosynthetic bacterium Ectothiorhodospira haloalkaliphila

2013 ◽  
Vol 453 (1) ◽  
pp. 304-307 ◽  
Author(s):  
A. A. Ashikhmin ◽  
Yu. E. Erokhin ◽  
Z. K. Makhneva ◽  
A. A. Moskalenko
Keyword(s):  
Protein Complexes ◽  
Photosynthetic Bacterium ◽  
Pigment Protein Complexes
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