The free energy change (Delta G degrees ) for the unfolding of immobilized yeast iso-1-cytochrome c (Cyt c) at nanoassemblies was measured by surface plasmon resonance (SPR) spectroscopy. Data show that SPR is sensitive to protein conformational changes, and protein solid interface exerts a major influence on bound protein stability. First, Cyt c was self-assembled on the Au film via the single...

Attempts to rationalize the kinetics of cytochrome c oxidation catalyzed by solubilized mitochondrial cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) have been based on assumptions of productive complex formation (Michaelis-Menten approach). However, the range of substrate concentrations used has not, in general, been sufficient to establish a general rate equation. D...

A strategy has been developed to express and purify a recombinant, nonfunctional axial-ligand mutant of iso-1-cytochrome c (Met-80-->Ala) in Saccharomyces cerevisiae in quantities necessary for extensive biophysical characterization. It involves coexpressing in the same plasmid (YEp213) the nonfunctional gene with a functional gene copy for complementation in a selective medium. The functional ...

The earliest events in protein folding involve the formation of simple loops. Observing the rates of loop closure under denaturing conditions can provide direct insight into the relative probability and sequence determinants for formation of loops of different sizes. The persistence of these initial contacts is equally important for efficient folding, so measurement of rates of loop breakage un...

The eukaryotic microsomal cytochrome P450 systems consist of a cytochrome P450 enzyme (P450) and a cytochrome P450 redox partner, which generally is a cytochrome P450 reductase (CPR) that supplies electrons from NADPH. However, alternative electron donors may exist such as cytochrome b5 reductase and cytochrome b5 (CBR and CYB5, respectively) via, which is NADH-dependent and are also anchored t...

The causative agent of leishmaniasis is the protozoan parasite Leishmania major. Part of the host protective mechanism is the production of reactive oxygen species including hydrogen peroxide. In response, L. major produces a peroxidase, L. major peroxidase (LmP), that helps to protect the parasite from oxidative stress. LmP is a heme peroxidase that catalyzes the peroxidation of mitochondrial ...

Defects in mitochondrial energy metabolism lead to severe human disorders, mainly affecting tissues especially dependent on oxidative phosphorylation, such as muscle and brain. Leigh Syndrome describes a severe encephalomyopathy in infancy, frequently caused by mutations in SURF1. SURF1, termed Shy1 in Saccharomyces cerevisiae, is a conserved assembly factor for the terminal enzyme of the respi...