The hydrogen-bonded water network in the oxygen-evolving complex of photosystem II

Polander, Brandon C.

Title:

The hydrogen-bonded water network in the oxygen-evolving complex of photosystem II

dc.contributor.advisor	Barry, Bridgette A.
dc.contributor.author	Polander, Brandon C.
dc.contributor.committeeMember	Oyelere, Adeboyega K.
dc.contributor.committeeMember	Lieberman, Raquel L.
dc.contributor.committeeMember	Curtis, Jennifer E.
dc.contributor.committeeMember	Sherrill, David
dc.contributor.department	Chemistry and Biochemistry
dc.date.accessioned	2014-01-13T16:19:35Z
dc.date.available	2014-01-13T16:19:35Z
dc.date.created	2013-12
dc.date.issued	2013-08-14
dc.date.submitted	December 2013
dc.date.updated	2014-01-13T16:19:35Z
dc.description.abstract	Protein dynamics play a key role in enzyme-catalyzed reactions. Vibrational spectroscopy provides a method to follow these structural changes and thereby describe the reaction coordinate as a function of space and time. A vibrational spectroscopic technique, reaction-induced FTIR spectroscopy, has been applied to the study of the oxygen-evolving complex (OEC) of photosystem II (PSII). In plant photosynthesis, PSII evolves oxygen from the substrate, water, by the accumulation of photo-oxidizing equivalents at the OEC. Molecular oxygen and protons are the products of this reaction, which is responsible for the maintenance of an aerobic atmosphere on earth. The OEC is a Mn4CaO5 cluster with nearby bound chloride ions. Sequentially oxidized states of the OEC are termed the S states. The dark-stable state is S1, and oxygen is released on the transition from S3 to S0. Using short laser flashes, individual S states are generated, allowing vibrational spectroscopy to be used to study these different oxidation states of the OEC. In current X-ray crystal structures, hydrogen bonds to water molecules are predicted to form an extensive network around the Mn4CaO5 cluster. In the OEC, four peptide carbonyl groups are linked to the water network, which extends to two Mn-bound and two Ca-bound water molecules. This dissertation discusses a vibrational spectroscopic method that uses these peptide carbonyl frequencies as reporters of solvatochromic changes in the OEC. This technique provides a new, high-resolution method with which to study water and protein dynamics in PSII and other enzymes.
dc.description.degree	Ph.D.
dc.format.mimetype	application/pdf
dc.identifier.uri	http://hdl.handle.net/1853/50222
dc.language.iso	en_US
dc.publisher	Georgia Institute of Technology
dc.subject	Photosystem II
dc.subject	Vibrational spectroscopy
dc.subject	Water oxidation
dc.subject	Amide carbonyl frequency
dc.subject	Reaction-induced FTIR
dc.subject.lcsh	Proteins
dc.subject.lcsh	Molecular dynamics
dc.subject.lcsh	Photosynthesis
dc.title	The hydrogen-bonded water network in the oxygen-evolving complex of photosystem II
dc.type	Text
dc.type.genre	Dissertation
dspace.entity.type	Publication
local.contributor.advisor	Barry, Bridgette A.
local.contributor.corporatename	School of Chemistry and Biochemistry
local.contributor.corporatename	College of Sciences
relation.isAdvisorOfPublication	3398b34c-4658-496b-84ec-43b16a2007e0
relation.isOrgUnitOfPublication	f1725b93-3ab8-4c47-a4c3-3596c03d6f1e
relation.isOrgUnitOfPublication	85042be6-2d68-4e07-b384-e1f908fae48a
thesis.degree.level	Doctoral