We have made surface plasmon resonance (SPR) measurements of yeast iso-1-cytochrome c (Cyt c) on a gold surface. Angle-resolved SPR curves are recorded as a function of urea concentration before and after self-assembly of the Cyt c. Exposure to a urea solution causes denaturation of Cyt c, which shifts the minimum in the SPR curve to a larger angle and decreases the signal amplitude. The Gibbs ...

A further function of cytochrome c (cyt c), beyond respiration, is realized outside mitochondria in the apoptotic program. In the early events of apoptosis, the interaction of cyt c with a mitochondrion-specific phospholipid, cardiolipin (CL), brings about a conformational transition of the protein and acquirement of peroxidase activity. The hallmark of cyt c with peroxidase activity is its par...

A novel third generation biosensor was developed based on one-shot adsorption of chemically-modified cytochrome c (cyt c) onto bare gold electrodes. In contrast to the classic approach which consists of attaching cyt c onto an active self-assembled monolayer (SAM) priory chemisorbed on gold, here short-chain thiol derivatives (mercaptopropionic acid, MPA) were chemically introduced on cyt c pro...

Syncytia arising from the fusion of cells expressing a lymphotropic HIV type 1-encoded envelope glycoprotein complex (Env) with cells expressing the CD4/CXC chemokine receptor 4 complex spontaneously undergo cell death. Here we show that this process is accompanied by caspase activation and signs of mitochondrial membrane permeabilization (MMP), including the release of intermembrane proteins s...

We have analyzed the structure of cytochrome c (cyt c) bound in a variety of complexes in which negatively charged molecular groups interact with the positively charged binding domain around the heme crevice of cyt c. Using resonance Raman spectroscopy, we could demonstrate that these interactions induce the same conformational changes as they were observed in the surface-enhanced resonance Ram...

A large number of pharmaceutically active compounds have a high affinity to acidic phospholipids; good examples are the cationic compounds lidocaine, propranolol, and gentamycin. These drugs influenced the lipid dynamics of liposomes composed of phosphatidylcholine and the acidic phosphatidylglycerol, as judged by the excimer/monomer emission intensity ratio for a pyrene-labeled phospholipid an...

This chapter addresses the role of mitochondria in apoptosis. Emphasis is put on the recently observed influence of ceramides on mitochondrial functions. We report here that N-acetylsphingosine (C2-ceramide), N-hexanoylsphingosine (C6-ceramide) and, to a much lesser extent, C2-dihydroceramide, induce cytochrome c (cyt c) release from isolated rat liver mitochondria. Ceramide-induced cyt c relea...

Over the past few years, work from a number of laboratories has shown that the ubiquinol :cytochrome c, (QH, :cyt. c,) oxidoreductase of the cyclic photosynthetic electron-transport chain of R hodopseudomonas sphaeroides is essentially similar to the mitochondria1 complex 111. Scheme 1 summarizes our present knowledge of the thermodynamics, kinetics and stoichiometry of the components of the ch...

It is proposed that direct electron transfer is dependent on the orientation of the heme plane in cytochrome c (cyt c) assembled on electrode surfaces. Orientation with the heme plane in cyt c parallel to the gold electrode surface favors the direct electron transfer, while vertical orientation of the heme plane makes the direct electron transfer difficult. A preferable electron transport pathw...

Mammalian cytochrome c (Cyt c) has two primary functions: transfer of electrons from the bc1 complex to cytochrome c oxidase (COX) as part of the mitochondrial electron transport chain (ETC), and participation in type II apoptosis. Several studies have indicated that components of the ETC can be phosphorylated, and we have recently shown that the Cyt c electron acceptor COX is phosphorylated on...