Author: Israel PechtPublisher:
ISBN:
Category :
Languages : en
Pages : 40
Book Description
Final Report on the Joint Research Project on Structure-function Relationship in the Electron Transfer Mediating Blue Copper Proteins
Final Report on Mechanisms of Electron Transfer Processes in Blue Copper Proteins
Author: Israel PechtStructure-function Analysis of Blue Copper Proteins
Author: Jeremy Daven KingPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 117
Book Description
Cofactors extend the chemistry of life. Redox reactions in photosynthesis, nitrogen fixation, and other metabolic pathways depend on metal cofactors. Copper is an essential element in biology, participating in redox reactions and biological catalysis. Copper proteins are classified by their copper centers as type-1, type-2, type-3, CuA, CuB, or Cuz. Type-1 proteins, such as azurin or plastocyanin, are primarily involved in electron transport. Type-1 centers are the most studied copper site at the spectroscopic and structural level. In the type-1 center, the copper cofactor is coordinated by a cysteine, two histidines, and generally a weak axial methionine. This coordination geometry gives rise to several ligand-to-metal charge-transfer transitions, producing a characteristic blue or green type-1 spectrum. In "blue" type-1 copper proteins, the cysteine-copper bond is exceptionally small (2.1 Å) and the methionine-copper bond is abnormally long (2.9 Å). In green type-1 copper proteins, the cysteine-copper bond elongates and the methionine-copper bond contracts. The redox range varies from +83 mV to over +1000 mV. Protein tuning modulates the large variations observed in the redox range and spectral properties. The mechanism of protein tuning is poorly understood. In chapter 2, I characterize a family of four blue copper proteins called auracyanins. The auracyanins, named A-D, were found to have a redox range from +83 mV to +423 mV, and range in color from blue to green. In chapter 3, I take advantage of the tuning variations within the auracyanin family to map the spectral changes to the protein-protein interaction domain. The protein-protein interaction domain has never previously been implicated in protein tuning. These results likely explain how seemingly energetically uphill electron transfer reactions commonly occur with copper proteins. In chapter 4, I perform mutagenesis on the weak axial ligand in auracyanin D. Auracyanin D is a green copper protein, and has the lowest redox potential ever measured for a copper protein. Significant work has been done on axial ligands in blue type-1 copper proteins, but never in green type-1 copper proteins. I found that substitutions to the axial ligand in green copper sites are much larger than their blue copper protein counterparts. In chapter 5, I conclude with a computational approach showing significant variation in the coordinating ligands of uncharacterized copper proteins. I believe examination of these proteins by a reverse biochemical approach will add more clarity to the role of protein tuning and expand the limits of copper tuning.
Investigating the Structure-function Relationships in Blue Copper Proteins
Author: John Ke MaSpectroscopic and Theoretical Studies of Copper Containing Electron Transfer Proteins
Author: Lipika BasumallickElectronic Structure Contributions of the Blue Copper Active Site to Reduction Potentials, Geometry, and Electron Transfer Pathways
Author: Jeffrey Allen GuckertPublisher:
ISBN:
Category :
Languages : en
Pages : 402
Book Description
An Investigation of the Relationship Between the Structure and Function of the Blue Copper Electron Transport Protein Plastocyanin Using Thin-layer, Steady-state Spectroelectro-chemistry
Author: Douglas Grant SandersonPublisher:
ISBN:
Category : Copper proteins
Languages : en
Pages : 424
Book Description
Copper-Containing Molecules
Author: Joan S. ValentinePublisher: Academic Press
ISBN: 0080544061
Category : Science
Languages : en
Pages : 493
Book Description
A wide range of researchers are currently investigating different properties and applications for copper-containing proteins. Biochemists researching metal metabolism in organisms ranging from bacteria to plants to animals are working in a completely different area of discovery than scientists studying the transportation and regulation of minerals and small molecule nutrients. They are both working with copper-containing proteins, but in very different ways and with differing anticipated outcomes.
Spectroscopic Investigations on Structure and Electron-transfer Kinetics of Blue-copper Proteins
Author: Cornelis M. GroeneveldPublisher:
ISBN:
Category :
Languages : en
Pages : 214
Book Description
Biological Electron Transfer in Copper Proteins
Author: Cynthia N. KiserPublisher:
ISBN:
Category : Charge exchange
Languages : en
Pages : 294
Book Description
Nature has used a variety of protein systems to mediate electron transfer. In this thesis I examine aspects of the control of biological electron transfer by two copper proteins that act as natural electron carriers.