Navigation Links
Scientists study the catalytic reactions used by plants to split oxygen from water
Date:4/3/2012

cyanobacteria, oxygen is produced by the accumulation of photo-induced oxidizing equivalents in a structure known as the oxygen-evolving complex (OEC). The OEC contains manganese and calcium ions. Illumination causes oxidation of manganese ions in the OEC. Short laser flashes can be used to step through the reaction cycle, which involves four sequential light-induced oxidation reactions. Oxygen is produced on the fourth step, and then is released from the OEC.

This so-called S state cycle resets with the binding of the substrate, water. Scientists have proposed that a hydrogen bond network, which includes multiple water molecules bound to manganese ions, calcium ions, and protein amide carbonyl (C=O) groups, forms an electrostatic network surrounding the OEC. In this scenario, the extensive hydrogen-bond network would then serve as a component of the catalyst, which splits off oxygen.

To study the process, Barry and graduate student Brandon Polander used precision FT-IR spectroscopy to describe how the network reacts to a short laser flash. The second harmonic of a pulsed Nd-Yag laser was used as the light source. This illumination causes the OEC to undergo one step in its catalytic cycle, the so-called S1 to S2 transition. An infrared spectrum was recorded before and after a laser flash to the photosystem sample, which was isolated from supermarket spinach.

The exquisite sensitivity of FT-IR spectroscopy allowed them to measure changes in the bond strength of the protein C=O groups. The energies of these C=O groups were used as markers of hydrogen bond strength. The brief laser flash oxidized a manganese ion and caused a change in the strength of the C=O bond, which reported an increase in hydrogen bonding to water molecules. When ammonia was added as an inhibitor, a decrease in C=O hydrogen bonding was observed instead. Addition of trehalose, which is known to change the ordering of water molecules at the surface of protein
'/>"/>

Contact: John Toon
jtoon@gatech.edu
404-894-6986
Georgia Institute of Technology Research News
Source:Eurekalert  

Page: 1 2 3

Related biology news :

1. Scripps Research Institute scientists find promising vaccine targets on hepatitis C virus
2. Dartmouth scientists track radioactive iodine from Japan nuclear reactor meltdown
3. Genetic mutation depicted in van Goghs sunflower paintings revealed by scientists
4. UGA scientists reveal genetic mutation depicted in van Goghs sunflower paintings
5. Scientists win $2 million to study new pathway in development and maintenance of lymphoma
6. WileyChina.com - Now Featuring Bespoke Pages for China’s Life Scientists
7. Salk scientists open new window into how cancers override cellular growth controls
8. Scientists discover new method of proton transfer
9. Brandeis scientists win prestigious prize for circadian rhythms research
10. American Society of Plant Biologists honors early career women scientists
11. Scientists produce eye structures from human blood-derived stem cells
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Scientists study the catalytic reactions used by plants to split oxygen from water
(Date:3/11/2015)... , Mar. 11, 2015 Research and Markets ... the "Access Control Market by Product, Application & ... report to their offering. , This ... to reach $10.4 billion by 2020, with an estimated ... report covers the products types such as contact cards ...
(Date:3/10/2015)...  NXT-ID, Inc. (NASDAQ: NXTD ... authentication company focused on the growing mobile commerce ... been named the "Number One Best Tech Gift ... Modern ( http://www.rethinkmodern.com/ ) is a web magazine focused ... that have a unique function or design.  ...
(Date:3/2/2015)... Ala. , March 2, 2015  Businesses ... processing. Data protection company Tharon Rankins Enterprises has ... that provides an ultra-safe way for businesses to ... their financial transactions. Beconux is ... Tharon Rankins Enterprises. Functioning similarly to an ATM ...
Breaking Biology News(10 mins):Global Access Control (Cards & Readers, Biometrics, Controllers, Management Software) Market 2015-2020 - Analysis of the $10 Billion Market 2NXT-ID's Wocket Smart Wallet Named Number One Best Tech Gift for 2015 by Rethink Modern 2NXT-ID's Wocket Smart Wallet Named Number One Best Tech Gift for 2015 by Rethink Modern 3NXT-ID's Wocket Smart Wallet Named Number One Best Tech Gift for 2015 by Rethink Modern 4Personal Data Protection Company Launches New Product 2
... University of the Negev researchers have developed techniques to ... adapt to hostile growing environments. In a recent ... Cell , BGU researchers were able show that by ... growth. Lateral root (LR) development is a highly regulated ...
... a paper published today in PNAS, scientists from the ... new insights into the workings of enzymes from a ... bacterium that causes tuberculosis. The new findings present possible ... pathogen but leave other microorganisms, which are beneficial to ...
... OAK RIDGE, Tenn., Feb. 14, 2011 -- Bioethanol ... become less costly because of plant engineering by The ... Ridge National Laboratory. In a paper published in ... , researchers describe their transgenic version of switchgrass as ...
Cached Biology News:2 in 1: Multi-tasking protein provides new approaches for anti-tuberculosis drugs 2New lignin 'lite' switchgrass boosts biofuel yield by more than one-third 2
(Date:3/26/2015)... The Market Element LLC, a leading inbound ... Designing Gig LLC to provide website design, development, and ... this alliance with Designing Gig represents a pivotal moment ... comprehensive, end-to-end, digital solution for our clients, which now ... Miller, president of The Market Element. “For small and ...
(Date:3/26/2015)... March 26, 2015 PAREXEL International ... clinical research organization , announced today ... agreement to acquire all of the business ... leading provider of specialized pharmacovigilance services, based ... collection, detection, assessment, monitoring, and prevention of ...
(Date:3/26/2015)... (PRWEB) March 26, 2015 WriteResult, a ... with researchers from Yale University’s School of Public Health ... study participants during a 4 month-long project. The goal ... providing low income families with free access to fresh ... and diet-related health concerns like high blood pressure, diabetes ...
(Date:3/25/2015)... ROCKVILLE, Md. , March 25, 2015 ... for the Vaccine Industry Excellence (ViE) Award "Best Clinical ... second consecutive year that Optimal has been selected as ... World Vaccine Congress, receiving a "Highly Recommended" distinction in ... generate recognition of the efforts, accomplishments, and positive contributions ...
Breaking Biology Technology:The Market Element LLC and Designing Gig LLC Form Strategic Alliance 2PAREXEL Announces Execution of Definitive Agreement to Acquire Quantum Solutions India, Strengthening Leadership In Pharmacovigilance Services 2PAREXEL Announces Execution of Definitive Agreement to Acquire Quantum Solutions India, Strengthening Leadership In Pharmacovigilance Services 3PAREXEL Announces Execution of Definitive Agreement to Acquire Quantum Solutions India, Strengthening Leadership In Pharmacovigilance Services 4Yale and New Haven Farms Improving Patient Health with WriteResult's myPROpad™ 2Yale and New Haven Farms Improving Patient Health with WriteResult's myPROpad™ 3Optimal Research Nominated 2015 Vaccine Industry Excellence (ViE) Award 2
... , , , , , , For 124 high-purity plasmid minipreps , ... Spin columns, , , ... , , Purification module: , ... Throughput: , 124 samples, , ...
... , , , , For purification of PCR products in low elution , volumes , ... Application: , PCR product cleanup, , ... Spin columns, , , Throughput: , ... DNA size range: , 70 bp 4 kb*, ...
... , , , , , ... System for cost-effective, fully automated, high-throughput DNA purification , ... chemistry eliminates the need , for a lysate ... a single plate and a simple bindwashelute procedure. The protocol , ...
Cached Biology Technology:DirectPrep 96 Miniprep System for cost-effective, high-throughput plasmid , DNA purification 2DirectPrep 96 Miniprep System for cost-effective, high-throughput plasmid , DNA purification 3DirectPrep 96 Miniprep System for cost-effective, high-throughput plasmid , DNA purification 4