Solar Energy News
SOLAR DAILY
Researchers discover quantum switch for regulating photosynthesis
The study entitled "Cryo-EM Structures of LHCII in Photo-active and Photo-protecting States Reveal Allosteric Regulation of Light-Harvesting and Excess Energy-Dissipation" was published on Nature Plants. (stock image only)
Researchers discover quantum switch for regulating photosynthesis
by Staff Writers
Beijing, China (SPX) Sep 04, 2023

Photosynthesis is a crucial process that allows plants to convert carbon dioxide into organic compounds using solar energy. Light-harvesting complex II (LHCII) is a complex of pigment molecules bound to proteins. It switches between two main functions-dissipating harmful excess light energy as heat under high light intensity through nonphotochemical quenching, and transferring absorbed light to the reaction center with almost a unit efficiency under low light.

Bioengineering studies have shown that accelerating the transition between these two functions can increase photosynthetic efficiency, e.g., soybean yields have been reported to increase by up to 33%. However, the atomic-level dynamic structural changes in LHCII that activate such allosteric regulation had not been previously elucidated.

ln this study, researchers led by Prof. WENG Yuxiang from the Institute of Physics of the Chinese Academy of Sciences, together with Prof. GAO Jiali's group from Shenzhen Bay Laboratory, combined single-particle cryo-electron microscopy (cryo-EM) studies of dynamic structures of LHCII at atomic resolution with multistate density functional theory (MSDFT) calculations of energy transfer between photosynthetic pigment molecules to identify the photosynthetic pigment quantum switch for intermolecular energy transfer.

As part of their work, they reported a series of six cryo-EM structures, including the energy transfer state with LHCII in solution and the energy quenching state with laterally confined LHCII in membrane nanodiscs under both neutral and acidic conditions.

Comparison of these different structures shows that LHCII undergoes a conformational change upon acidification. This change allosterically alters the inter-pigment distance of the fluorescence quenching locus Lutein1 (Lut1)-Chlorophyll612 (Chl612) only when LHCII is confined in membrane nanodiscs, leading to the quenching of excited Chl612 by Lut1. Thus, LHCII confined with lateral pressure (e.g., aggregated LHCII) is a prerequisite for non-photochemical quenching (NPQ), whereas acid-induced conformational change enhances fluorescence quenching. Through MSDFT calculations of cryo-EM structures and the known crystal structure in quenched states, together with transient fluorescence experiments, a significant quantum switching mechanism of LHCII has been revealed with Lut1-Chl612 distance as the key factor.

This distance regulates the energy transfer quantum channel in response to the lateral pressure on LHCII and the conformational change, that is, a slight change at its critical distance of 5.6 A would allow reversible switching between light harvesting and excess energy dissipation. This mechanism enables a rapid response to changes in light intensity, ensuring both high efficiency in photosynthesis and balanced photoprotection with LHCII as a quantum switch.

Previously, these two research groups had collaborated on molecular dynamics simulations and ultrafast infrared spectroscopy experiments and had proposed that LHCII is an allosterically regulated molecular machine. Their current experimental cryo-EM structures confirm the previously theoretically predicted structural changes in LHCII.

This study entitled "Cryo-EM Structures of LHCII in Photo-active and Photo-protecting States Reveal Allosteric Regulation of Light-Harvesting and Excess Energy-Dissipation" was published on Nature Plants.

This research was supported by projects from the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Shenzhen Municipal Science and Technology Innovation Commission.

Research Report:Cryo-EM structures of LHCII in photo-active and photo-protecting states reveal allosteric regulation of light harvesting and excess energy dissipation

Related Links
Institute of Physics
All About Solar Energy at SolarDaily.com

Subscribe Free To Our Daily Newsletters
Tweet

RELATED CONTENT
The following news reports may link to other Space Media Network websites.
SOLAR DAILY
New insight for stabilizing halide perovskite via thiocyanate substitution
Tokyo, Japan (SPX) Sep 04, 2023
a-FAPbI3, a promising solar cell material with a cubic perovskite structure that is metastable at room temperature, can be stabilized by introducing a pseudo-halide ion like thiocyanate (SCN-) into its structure, demonstrated by Tokyo Tech researchers in a new study. Their finding provides new insights into the stabilization of the a-phase via grain boundary and pseudo-halide engineering. The light we receive every day from the Sun, if harnessed efficiently, can help us tackle the ongoing global e ... read more

SOLAR DAILY
Making aviation fuel from biomass

Chevron, partners develop a transportation fuel using animal waste as a feedstock

Illinois research leading to cleaner propane production method

Transforming flies into degradable plastics

SOLAR DAILY
UN calls for age limits for AI tools in schools

Tencent claims new AI chat bot skills comparable to ChatGPT

Baidu leads public rollout of AI chatbots in China

ChatGPT turns to business as popularity wanes

SOLAR DAILY
UK eases effective ban on onshore wind in England

China, US lift wind turbine sales: study

Interior Department holds offshore wind energy auction for Gulf

DLR opens wind energy research farm in Krummendeich

SOLAR DAILY
Italy postpones regional ban on old diesel vehicles

Swedish opposition slams government tax cut on petrol

Self-driving car revolution is coming, but slowly

Modern cars are a data privacy 'nightmare' says study

SOLAR DAILY
Alumnus' thermal battery helps industry eliminate fossil fuels

Jeep owner Stellantis invests $100 mn in US lithium

DoE announces $112 million for research on computational projects in fusion energy sciences

US lab repeats nuclear fusion feat, with higher yield

SOLAR DAILY
Kazakh leader calls for rare vote on nuclear plant

Sweden to clear obstacles for new nuclear reactors

Ukraine nuclear plants fully operational for winter: operator

No explosives found on Zaporizhzhia nuclear plant roofs: IAEA

SOLAR DAILY
African leaders to push for finance at climate summit

Controversial plan to develop Toronto green area under review

Billions pledged for green development at Africa climate talks

Free electricity boon for Norway's two biggest cities

SOLAR DAILY
Deforestation in Brazil Amazon falls, more Indigenous reserves approved

Malaysia's Forest City teeters over China property giant woes

Helping or hindering? US scientists debate how to save giant sequoias

More Brazil Supreme Court judges vote on Indigenous land rights case

Subscribe Free To Our Daily Newsletters




The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.