Probing Electron Transport through and around Photosystem II in vivo by the Combined Use of Photoacoustic Spectroscopy and Chlorophyll Fluorometry

1998 ◽  
Vol 38 (3) ◽  
pp. 247-256 ◽  
Author(s):  
Michel Havaux
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Photoacoustic Spectroscopy ◽  
Combined Use

Electron transport to oxygen mitigates against the photoinactivation of Photosystem II in vivo

1996 ◽  
Vol 50 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Youn-II Park ◽  
Wah Soon Chow ◽  
C. Barry Osmond ◽  
Jan M Anderson
Keyword(s):  
Electron Transport ◽  
Photosystem Ii

Research note: Energy partitioning in photosystem II complexes subjected to photoinhibitory treatment

2007 ◽  
Vol 34 (3) ◽  
pp. 214 ◽  
Author(s):  
Dmytro Kornyeyev ◽  
Luke Hendrickson
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Excitation Energy ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Photosynthetic Electron Transport ◽  
Energy Partitioning ◽  
Simple Equations

Chlorophyll a fluorescence measured in vivo is frequently used to study the role of different processes influencing the distribution of excitation energy in PSII complexes. Such studies are important for understanding the regulation of photosynthetic electron transport. However, at the present time, there is no unified methodology to analyse the energy partitioning in PSII. In this article, we critically assess several approaches recently developed in this area of research and propose new simple equations, which can be used for de-convolution of non-photochemical energy quenching in PSII complexes.

Irreversibly Binding Photosynthetic Electron Transport Inhibitors II. Halogen-Substituted 1,4-Naphthoquinones and Halogenmethyl-1,4-quinones

1987 ◽  
Vol 42 (6) ◽  
pp. 693-697 ◽  
Author(s):  
Walter Oettmeier ◽  
Ralf Dostatni ◽  
Hans-Joachim Santel
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Binding Affinity ◽  
Alkylating Agents ◽  
Photosynthetic Electron Transport ◽  
Hydrogen Halide ◽  
Covalent Linkage ◽  
Transport Inhibitors ◽  
Preincubation Time

Several halogen-substituted 1,4-naphthoquinones have been synthesized and found to be effective photosystem II inhibitors. Due to their properties as vinylogous acid halides they can react with nucleophiles under formation of a covalent linkage. In their presence other photosystem II herbicides show a decreased binding affinity. This decrease is dependent from the preincubation time. Halogenmethyl-1,4-quinones also turned out to be efficient photosystem II inhibitors and. in addition, possessed herbicidal in vivo activity. They function as “bioreductive alkylating agents” in a way that after reduction they can split off hydrogen halide under formation of a o-quinonemethide. This quinonemethide can react with nucleophilic groups in proteins.

Inhibition of Photosynthetic Electron Transport by Halogenated 4-Hydroxy-pyridines

1985 ◽  
Vol 40 (5-6) ◽  
pp. 391-399 ◽  
Author(s):  
A. Trebst ◽  
B. Depka ◽  
S. M. Ridley ◽  
A. F. Hawkins
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Electron Flow ◽  
Essential Element ◽  
Photosynthetic Electron Transport ◽  
Cyclic Electron Flow ◽  
Acceptor Side

Abstract Herbicidal halogen substituted 4-hydroxypyridines are inhibitors of photosynthetic electron flow in isolated thylakoid membranes by interfering with the acceptor side of photosystem II. Tetrabromo-4-hydroxypyridine, the most active compound found, has a pI50-value of 7.6 in the inhibition of oxygen evolution in both the reduction of an acceptor of photosystem I and an acceptor of photosystem II. The new inhibitors displace both metribuzin and ioxynil from the membrane. The 4-hydroxypyridines, like ioxynil, have unimpaired inhibitor potency in Tristreated chloroplasts, whereas the DCMU-type family of herbicides does not. It is suggested that 4-hydroxypyridines are complementary to phenol-type inhibitors, and a common essential element is proposed. The 4-hydroxypyridines do not inhibit photosystem I or non-cyclic electron flow through the cytochrome b/f complex. But they do have a second inhibition site in photosynthetic electron transport since they inhibit ferredoxin-catalyzed cyclic electron flow, indicating an antimycin-like property. A comparison of the in vitro potency of the compounds with the in vivo potency shows no correlation. A major herbicidal mode of action of the group is related to the inhibition of carotenoid synthesis, and access to the chloroplast lamellae in vivo for inhibition of electron transport may be restricted.

IN VIVO PHOTOACOUSTIC SPECTROSCOPY OF THE SKIN

1983 ◽  
Vol 44 (C6) ◽  
pp. C6-413-C6-418 ◽  
Author(s):  
P. Poulet ◽  
J. Chambron
Keyword(s):  
Photoacoustic Spectroscopy

Photosystem II Inhibition by Pyran-enamine Derivatives

1993 ◽  
Vol 48 (3-4) ◽  
pp. 163-167
Author(s):  
Koichi Yoneyama ◽  
Yoshihiro Nakajima ◽  
Masaru Ogasawara ◽  
Hitoshi Kuramochi ◽  
Makoto Konnai ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Thylakoid Membranes ◽  
Major Determinant ◽  
Ps Ii ◽  
Structure Activity Relationships ◽  
Structure Activity

Abstract Through the studies on structure-activity relationships of 5-acyl-3-(1-aminoalkylidene)-4-hydroxy-2 H-pyran-2,6(3 H)-dione derivatives in photosystem II (PS II) inhibition, overall lipophilicity of the molecule was found to be a major determinant for the activity. In the substituted N -benzyl derivatives, not only the lipophilicity but also the electronic and steric characters of the substituents greatly affected the activity. Their mode of PS II inhibition seemed to be similar to that of DCMU , whereas pyran-enamine derivatives needed to be highly lipophilic to block the electron transport in thylakoid membranes, which in turn diminished the permeability through biomembranes.

scholarly journals Targeting Erbin in B cells for therapy of lung metastasis of colorectal cancer

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Tong Shen ◽  
Jing-Lin Liu ◽  
Chu-Yi Wang ◽  
Youlutuziayi Rixiati ◽  
Shi Li ◽  
...  
Keyword(s):  
B Cells ◽  
Lung Metastasis ◽  
Lung Metastases ◽  
Pdz Domain ◽  
Clinical Samples ◽  
Key Factors ◽  
Combined Use ◽  
Iga Production

AbstractThe mechanisms and key factors involved in tumor environments for lung metastasis of CRC are still unclear. Here, using clinical samples from lung metastases of CRC patients, we found that intestinal immune network for IgA production was significantly dysregulated in lung metastases of CRC. Single-cell RNA sequencing discovered a subtype of B cells positive for Erbin, one member of the leucine-rich repeat and PDZ domain (LAP) family, was involved in the lung metastases. Erbin deletion in B cells suppressed lung metastasis of CRC in vivo. And, deletion of Erbin in B cells enhanced the killing effects of CD8+ T cells on tumor cells. Mechanistically, Erbin knockout attenuated TGFβ-mediated suppression of migration of CXCR5+ IgA+ cells and STAT6-mediated PD1 expression. Our study uncovered a key role of Erbin in regulating PD1+ IgA+ B cells in lung metastasis of CRC. Targeting Erbin as well as combined use of neutralizing B cells and antibodies neutralizing PD1 suppresses lung metastasis of CRC in mice, suggesting the potential option for treatment of lung metastasis of CRC.

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