RATIONALE An increase in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) in pulmonary arterial smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important stimulus for PASMC proliferation and pulmonary vascular remodeling. The dihydropyridine Ca(2+) channel blockers, such as nifedipine, have been used for treatment of idiopathic pulmonary arterial hyperten...

Since the (re)discovery of cytochrome c (cyt c) in the early 1920s and subsequent detailed characterization of its structure and function in mitochondrial electron transport, it took over 70 years to realize that cyt c plays a different, not less universal role in programmed cell death, apoptosis, by interacting with several proteins and forming apoptosomes. Recently, two additional essential f...

A covalent complex between rabbit hepatic microsomal cytochromes P-450 isozyme 2 (LM2) and b5 was created and purified to greater than 95% homogeneity. The purified complex was largely comprised of the two cytochromes covalently attached at the interface of the functional electron transfer-effector complex as shown by the following evidence. The spin state of the LM2 within the complex was grea...

Cyt c550 and 12 kDa protein are two extrinsic proteins of photosystem II (PSII) found in cyanobacteria and some eukaryotic algae. The binding patterns of these two extrinsic proteins are different between cyanobacterial (Thermosynechococcus vulcanus) and red algal (Cyanidium caldarium) PSIIs [Shen and Inoue (1993) Biochemistry 32: 1825; Enami et al. (1998) Biochemistry 39: 2787]. In order to el...

Choline dioctylsulfosuccinate [Cho][AOT] (a surface active ionic liquid) has been found to induce all-α to α + β conformational transition in the secondary structure of enzyme cytochrome c (Cyt c) with an enhanced peroxidase activity in its aqueous vesicular phase at pH 7.0. [Cho][AOT] interacted with Cyt c distinctly at three critical concentrations (aggregation C1, saturation C2 and vesicular...

Hypoxic pulmonary vasoconstriction is caused by a rise in cytosolic Ca(2+) ([Ca(2+)](cyt)) in pulmonary artery smooth muscle cells (PASMC) via multiple mechanisms. PASMC consist of heterogeneous phenotypes defined by contractility, proliferation, and apoptosis as well as by differences in expression and function of various genes. In rat PASMC, hypoxia-mediated decrease in voltage-gated K(+) (Kv...

Membrane association and detachment of cytochrome c (cyt c) in millisecond to second time domain were investigated by stopped-flow fluorescence spectroscopy monitoring the efficiency of energy transfer from a pyrene-fatty acid containing phospholipid derivative, 1-palmitoyl-2-[10-(pyren-1-yl)-decanoyl]-sn-glycero-3-phosphoglyce rol (PPDPG, mole fraction X = 0.01) to the heme of the cyt c. Large...

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...

BACKGROUND To investigate the mechanism by which rare cases of spinal local anesthetic (LA) neurotoxicity occur, we have tested the hypotheses that LAs elevate cytoplasmic calcium (Ca2+(cyt)), that this is associated with a neurotoxic effect, and that lidocaine and bupivacaine differ in their neurotoxicity. METHODS Neurons of the ND7 cell culture line, derived from dorsal root ganglion, were ...

Mixed monomolecular films of cytochrome (Cyt) and chlorophyll (Chl) were spread at a nitrogen-water interface. A large interaction is observed between reduced Cyt f and Chl a in a mixed film. Oxidized Cyt f and Chl a in a mixed film show little evidence for interaction. Mixed monomolecular films of Chl a with either reduced or oxidized Cyt c appears to result in denaturation of the protein at t...