Effects of chlorophyll a, chlorophyll b, and xanthophylls on the in vitro assembly kinetics of the major light-harvesting chlorophyll a/b complex, LHCIIb11Edited by G. von Heijne

2001 ◽  
Vol 308 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Dirk Reinsberg ◽  
Katja Ottmann ◽  
Paula J Booth ◽  
Harald Paulsen
Keyword(s):  
Chlorophyll A ◽  
Light Harvesting ◽  
Chlorophyll B ◽  
In Vitro Assembly ◽  
Assembly Kinetics ◽  
Kinetics Of

scholarly journals In Vitro Assembly Kinetics of Cytoplasmic Intermediate Filaments: A Correlative Monte Carlo Simulation Study

PLoS ONE ◽  
2016 ◽  
Vol 11 (6) ◽  
pp. e0157451 ◽  
Author(s):  
Norbert Mücke ◽  
Stefan Winheim ◽  
Holger Merlitz ◽  
Jan Buchholz ◽  
Jörg Langowski ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Intermediate Filaments ◽  
Simulation Study ◽  
Monte Carlo Simulation Study ◽  
In Vitro Assembly ◽  
Assembly Kinetics ◽  
Kinetics Of

Reduction of the Formyl Group of Zinc Pheophorbide b in vitro and in vivo: a Model for the Chlorophyll b to a Transformation

1996 ◽  
Vol 51 (3-4) ◽  
pp. 185-194 ◽  
Author(s):  
Verena Scheumann ◽  
Michael Helfrich ◽  
Siegrid Schoch ◽  
Wolfhart Rüdiger
Keyword(s):  
Nmr Spectroscopy ◽  
Chlorophyll A ◽  
Chemical Reduction ◽  
Chlorophyll B ◽  
Formyl Group ◽  
Pheophorbide A ◽  
Pheophytin A ◽  
H Nmr

Abstract The chemical reduction of the formyl group of pheophorbide b with sodium cyanoborohy­ dride in methanol leads to 71-methoxy-and 71-hydroxy-pheophorbide a. The same reaction with zinc pheophorbide b yields in addition zinc pheophorbide a. This was characterized by mass and 1H -NMR spectroscopy. Infiltration of zinc pheophorbides a and b and of zinc 71-hydroxy-pheophorbide a into etiolated oat leaves yielded phytylated products. The best yield in the esterification was obtained with 71-hydroxy-pheophorbide a. Analysis of the products revealed the formation of zinc pheophytin a from all infiltrated compounds. The significance for the transformation of chlorophyll b into chlorophyll a is discussed.

scholarly journals In Vitro Enzymatic Activity Assays Implicate the Existence of the Chlorophyll Cycle in Chlorophyll b-Containing Cyanobacteria

2019 ◽  
Vol 60 (12) ◽  
pp. 2672-2683 ◽  
Author(s):  
HyunSeok Lim ◽  
Ayumi Tanaka ◽  
Ryouichi Tanaka ◽  
Hisashi Ito
Keyword(s):  
Enzymatic Activity ◽  
Chlorophyll A ◽  
Developmental Stages ◽  
Enzymatic Activities ◽  
Light Acclimation ◽  
Chlorophyll B ◽  
Light Conditions ◽  
Chl A ◽  
Shallow Seas

Abstract In plants, chlorophyll (Chl) a and b are interconvertible by the action of three enzymes—chlorophyllide a oxygenase, Chl b reductase (CBR) and 7-hydroxymethyl chlorophyll a reductase (HCAR). These reactions are collectively referred to as the Chl cycle. In plants, this cyclic pathway ubiquitously exists and plays essential roles in acclimation to different light conditions at various developmental stages. By contrast, only a limited number of cyanobacteria species produce Chl b, and these include Prochlorococcus, Prochloron, Prochlorothrix and Acaryochloris. In this study, we investigated a possible existence of the Chl cycle in Chl b synthesizing cyanobacteria by testing in vitro enzymatic activities of CBR and HCAR homologs from Prochlorothrix hollandica and Acaryochloris RCC1774. All of these proteins show respective CBR and HCAR activity in vitro, indicating that both cyanobacteria possess the potential to complete the Chl cycle. It is also found that CBR and HCAR orthologs are distributed only in the Chl b-containing cyanobacteria that habitat shallow seas or freshwater, where light conditions change dynamically, whereas they are not found in Prochlorococcus species that usually habitat environments with fixed lighting. Taken together, our results implicate a possibility that the Chl cycle functions for light acclimation in Chl b-containing cyanobacteria.

Kinetics of the appearance of mRNA for light-harvesting chlorophyll a/b protein in polysomes of barley

Planta ◽  
1980 ◽  
Vol 148 (5) ◽  
pp. 448-452 ◽  
Author(s):  
Michael Müller ◽  
Maija Viro ◽  
Christiane Balke ◽  
Klaus Kloppstech
Keyword(s):  
Chlorophyll A ◽  
Light Harvesting ◽  
Kinetics Of

scholarly journals Leaf Senescence of Postproduction Poinsettias in Low-light Stress

1994 ◽  
Vol 119 (5) ◽  
pp. 1006-1013 ◽  
Author(s):  
J. Lorene Embry ◽  
Eugene A. Nothnagel
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Light Harvesting ◽  
Light Stress ◽  
Chlorophyll B ◽  
Excitation Spectra ◽  
Low Light ◽  
Fluorescence Excitation ◽  
Fluorescence Excitation Spectra ◽  
Low Light Stress

Photosynthetic light harvesting was investigated under low-light stress conditions relevant to the problem of interior longevity of potted ornamental plants. Comparisons of leaf pigment levels and chlorophyll fluorescence excitation spectra were made for `Gutbier V-10 Amy' poinsettia (Euphorbia pulcherrima Willd.), which has poor interior longevity, and `Eckespoint Lilo' poinsettia, which has superior interior longevity. The results show that `Eckespoint Lilo' had higher total chlorophyll content per leaf area and lower chlorophyll a: chlorophyll b ratio than `Gutbier V-10 Amy'. In low-light stress, `Eckespoint Lilo' retained its chlorophyll or even accumulated higher levels than in high light, while `Gutbier V-10 Amy' did not exhibit higher chlorophyll retention in low light. Both cultivars acclimatized to low-light stress by decreasing the chlorophyll a: chlorophyll b ratio, and this acclimatization was evident sooner in younger, outer-canopy leaves above the pinch than in older leaves below the pinch. Both cultivars also increased the chlorophyll: carotenoid ratio in low light. These changes in pigment composition, which were essentially structural changes, were reflected in functional changes in light harvesting, as assessed by measurements of chlorophyll fluorescence excitation spectra.

scholarly journals Temperature-dependent Self assembly of biofilaments during red blood cell sickling

2021 ◽  
Author(s):  
Arabinda Behera ◽  
Oshin Sharma ◽  
Debjani Paul ◽  
Anirban Sain
Keyword(s):  
Self Assembly ◽  
Kinetic Monte Carlo ◽  
Lag Time ◽  
Vital Role ◽  
Temperature Dependent ◽  
Opposite Case ◽  
Assembly Kinetics ◽  
The Mean ◽  
Kinetics Of

Molecular self-assembly plays vital role in various biological functions. However, when aberrant molecules self-assemble to form large aggregates, it can give rise to various diseases. For example, the sickle cell disease and Alzheimer’s disease are caused by self-assembled hemoglobin fibers and amyloid plaques, respectively. Here we study the assembly kinetics of such fibers using kinetic Monte-Carlo simulation. We focus on the initial lag time of these highly stochastic processes, during which self-assembly is very slow. The lag time distributions turn out to be similar for two very different regimes of polymerization, namely, a) when polymerization is slow and depolymerization is fast, and b) the opposite case, when polymerization is fast and depolymerization is slow. Using temperature dependent on- and off-rates for hemoglobin fiber growth, reported in recent in-vitro experiments, we show that the mean lag time can exhibit non-monotonic behaviour with respect to change of temperature.

scholarly journals Genetic Complementation and Kinetic Analyses ofRhodobacter capsulatus ORF1696 Mutants Indicate that the ORF1696 Protein Enhances Assembly of the Light-Harvesting I Complex

1998 ◽  
Vol 180 (7) ◽  
pp. 1759-1765 ◽  
Author(s):  
C. S. Young ◽  
R. C. Reyes ◽  
J. T. Beatty
Keyword(s):  
Absorption Spectrum ◽  
Parental Strain ◽  
Rhodobacter Capsulatus ◽  
Light Harvesting ◽  
Major Effect ◽  
Complex Assembly ◽  
Mutant Strains ◽  
Assembly Kinetics ◽  
Kinetics Of ◽  
Steady State Absorption

ABSTRACT Rhodobacter capsulatus ORF1696 mutant strains were created by insertion of antibiotic resistance cartridges at different sites within the ORF1696 gene in a strain that lacks the light-harvesting II (LHII) complex. Steady-state absorption spectroscopy profiles and the kinetics of the light-harvesting I (LHI) complex assembly and decay were used to evaluate the function of the ORF1696 protein in various strains. All of the mutant strains were found to be deficient in the LHI complex, including one (ΔNae) with a disruption located 13 codons before the 3′ end of the gene. A 5′-proximal disruption after the 31st codon of ORF1696resulted in a mutant strain (ΔMun) with a novel absorption spectrum. The two strains with more 3′ disruptions (ΔStu and ΔNae) were restored nearly to the parental strain phenotype when transcomplemented with a plasmid expressing the ORF1696 gene, but ΔMun was not. The absorption spectrum of ΔMun resembled that of a strain which had a polar mutation in ORF1696. We suggest that a rho-dependent transcription termination site exists between the MunI and proximal StuI sites ofORF1696. A comparison of LHI complex assembly kinetics showed that assembly occurred 2.6-fold faster in the parental strain than in strain ΔStu. In contrast, LHI complex decay occurred 1.7-fold faster in the ORF1696 parental strain than in ΔStu. These results indicate that the ORF1696 protein has a major effect on LHI complex assembly, and models of ORF1696 function are proposed.

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