Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"Midpoint potential"”.
-
The Physical Chemistry Underlying the Assembly and Midpoint Potential Control in a Series of Designed Protein-Maquettes
… achieved, and what are the oxidation-reduction potentials, is critical for understanding the rules of assembly and function of the different activities performed. In the growing field of research attempting to make man-made oxidoreductases, the same understanding is required for progress to be …
-
Redox active tyrosine residues in biomimetic beta hairpins
… create a peptide environment that lowers the midpoint potential of tyrosine in beta hairpins. Moreover, these interactions contribute equally to control the midpoint potential. The data also show that hydrogen bonding is not the sole determinant of the midpoint potential of tyrosine. Finally, …
-
Thioredoxin-mediated reduction of photosynthetic carbon reduction enzymes following chilling in the light
… The chilling treatment had no effect on the midpoint potential of the regulatory sulfhydryl groups ($-$310 mV), indicating no direct chilling damage to the enzyme. Thiol labeling of FBPase in vivo showed that there was a 60% decrease in sulfhydryl labeling following chilling, indicating that …
-
Biophysical investigation of electron transfer between high-potential hemes in c subunit and special pair of reaction center protein of photosynthetic bacteria Rhodopseudomonas viridis
… center complex. Two of them are high redox midpoint potential hemes (cyt-c559; Em = 380 mV and cyt-c556; Em = 310 mV) and other two are low midpoint potential hemes (cyt-c552; Em = 0 mV and cyt-c554; Em = $-$60 mV). The temperature dependence of the rate of oxidation of high potential …
-
Investigation of the Interaction Between Cytochrome b(H) and the Q(i)-Site in Rhodobacter Sphaeroides
… of this work are that the pH dependence of the midpoint potential of cytochrome bH differs substantially from what was published previously; a high potential component of bH remains even in the presence of Antimycin, and the thermodynamic properties of bH are substantially modified in strains …
-
Investigating novel bacterial laccases with biotechnologically relevant attributes
… biotechnological fields due to their high-redox potential. However, they exhibit poorer activity in alkaline pH and high temperature conditions when compared to their lowredox bacterial counterparts. These discrepancies in oxidative abilities have been correlated to differences in axial ligands …
-
Structure and function relationship of cytochrome c studied by NMR and molecular dynamics simulations
… structural waters in both redox states reveal potentially significant redox-dependent structural changes. The orientation of the electron spin g-tensor was determined and the resulting pseudocontact shifts were used not only to independently confirm observed structural differences but also to …
-
Supercharging: An Investigation into the Effects of External Amino Acid Residue Charge on the Solubility and Internal Electric Character of Bound Ligands in a Heme-Binding de novo-Designed Protein
… understand natural protein dynamics and as a potential resource in biomedical and industrial applications. In this work I describe the modification of a simple, well-characterized heme-binding protein by altering side chain residue identities on the hydrophilic surface of the protein to …
-
Purification and Characterization of the Cytochrome BC(1) Complex From Rhodobacter Sphaeroides
… $c\sb1$ possessed spectral features and redox midpoint potentials similar to those found in chromatophores. Redox titrations of the Rieske iron-sulfur center were monitored by low-temperature EPR spectroscopy, and its midpoint potential was shifted from +280 to +315 mV upon addition of …
-
The System I and System III Holocytochrome c Synthases in Cytochrome c Biogenesis
… were identified: TM-His1 and TM-His2), and the midpoint potential of the heme b was determined and found to be consistent with its involvement in a critical redox reaction underlying the synthetase reaction. Additionally, a long-suspected interaction between CcmF and the periplasmic heme …
-
Deconvoluting the Engineering and Assembly Instructions for Complex Iii Activity
… the Qo site; one electron is delivered to a high potential chain containing an iron-sulfur cluster, cytochrome c1 and cytochrome c2, and a second electron is transferred to a low potential chain that terminates at the Qi site. All Complex III electron tunneling reactions are reversible, and a …
-
Computational Insights Into The Oxygen Evolving Complex Of Photosystem ΙΙ
… In the simulation, the electrochemical potential (Eh) is varied to oxidize the OEC. The MC sampling allows the Ã?µ-oxo-bridges, terminal waters and amino acid residues to change their protonation states and/or their rotamer position to respond to the Mn oxidation. In addition, chloride …
-
Investigation of photoprotection of photosystem II by cytochrome b559
… within photosystem II can protect against potentially damaging redox states. Experiments using photosynthetic membranes poised at different ambient redox potentials demonstrate that light-induced damage to photosystem II is controlled by a redox component within the reaction center with a …
-
CHEMICAL AND PHYSICAL CHARACTERIZATION OF COMPLEX III; THE OXIDATIVE REACTION MECHANISM
… by hindered bis-imidazole protoheme. The midpoint potentials for the b and c(,1) cytochrome were measured using MCD and EPR. A value of 270 mV was obtained for cytochrome c(,1) while the midpoint potentials found for the two species of cytochrome b varied with temperatures, viz. 62 and -20 …
-
New Insights into Mycofactocin Biosynthesis, Structure and Function
… for catalysis. In addition, we measured the midpoint potentials of the clusters to provide insights into the redox flipping mechanism of MftC. Furthermore, we reconstituted the activity of MftE and showed that it selectively hydrolyzes MftA* to form MftA (1-28) and a …
-
The Structure-Function Interface in the Cytochrome Bc1 Complex Family
… in modification of the spectrum and redox potential of the bL-heme. Mutations of Tyr-156, located close to the iron-sulfur cluster in the ISP to Leu, Phe or Trp led to alteration of the midpoint potential of the ISP. Slowing in the rate of quinol oxidation correlated with a modified redox …
-
Structure and function studies of polar mutants of the QA pocket in the bacterial photosynthetic reaction center of Rhodobacter sphaeroides
… ubiquinones and the protein must tune the midpoint potential (Em) of each quinone to make electron transfer from QA to QB favorable. Using site directed mutagenesis together with the techniques of X-ray crystallography, flash kinetic spectroscopy, and quinone substitution, I was able to …
-
Characterisation of cytochrome c MtoD from the iron-oxidising autotroph sideroxydans lithotrophicus ES-1
… generated for the fixation of CO2. To probe the potential electron transfer pathways in S. lithotrophicus, MtoD was overexpressed in S. oneidensis, purified and characterised using biophysical, structural and spectroelectrochemical methods. The primary structure of MtoD contains a single CXXCH …
-
Studies on the structure, function and mechanisms of the cbb3 type cytochrome c oxidase from Vibrio cholerae and the cytochrome bo3 ubiquinol oxidase from Escherichia coli
… conserving energy in the form of electrochemical potential. Different subfamilies of CcO are identified mainly based on the sequence homology. They vary in a wide range of aspects but also share certain conserved features: a) A binuclear center consisted of CuB and a high spin heme for catalysis; …