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R Bisson

Publications and source records attributed to R Bisson.

At least 37 records · Page 2Linked to original sources
PubMed1987

Isolation and characterization of cytochrome c oxidase from bird and fish heart mitochondria.

1. Several bird and fish heart mitochondrial cytochrome c oxidases have been isolated with a rapid and simple method involving hydrophobic and affinity chromatography. 2. Their spectrophotometric and kinetic properties are very similar to those of the mammalian enzymes. 3. These oxidases show a polypeptide composition simpler than the mammalian enzymes being composed of 9-10, instead of 13, different polypeptides. 4. These data suggest that the complexity of the mitochondrial heart oxidase increases with the stage of evolution.

Animals↗
PubMed1986

Two different forms of cytochrome c oxidase can be purified from the slime mold Dictyostelium discoideum.

Cytochrome c oxidase was purified from mitochondria of Dictyostelium discoideum cells harvested at different phases of the vegetative stage. Comparison of the preparations by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicates that the smallest enzyme subunit present during exponential growth is replaced by a larger polypeptide component in the stationary phase. The two polypeptides are structurally and immunologically unrelated.

Antigen-Antibody Complex↗
PubMed1986

ATP binding to bovine heart cytochrome c oxidase. A photoaffinity labelling study.

ATP influences the kinetic properties of cytochrome c oxidase. A photoactivatable radioactive ATP analogue was used to localize the nucleotide-binding site on the bovine heart enzyme. Subunits IV and VIII were specifically labelled, suggesting that these two nuclear-coded polypeptides may play a regulatory role on the oxidase functions.

Adenosine Triphosphate↗
PubMed1985

Transmembrane topology of acetylcholine receptor subunits probed with photoreactive phospholipids.

The domains of the acetylcholine receptor subunits that contact the lipid phase were investigated by hydrophobic photolabeling of receptor-rich membrane fragments prepared from Torpedo marmorata and Torpedo californica electric organs. The radioactive arylazido phospholipids used carry a photoreactive group, either at the level of the lipid polar head group (PCI) or at the tip of the aliphatic chain (PCII), and thus probe respectively the "superficial" and "deep" regions of the lipid bilayer. The four subunits of T. marmorata and T. californica acetylcholine receptor reacted with both the PCI and PCII probes and thus are all exposed to the lipid phase. Ligands known to stabilize different conformations of the acetylcholine receptor (nicotinic agonists, snake alpha-toxin, and noncompetitive blockers) did not cause any significant change in the labeling pattern. The acetylcholine receptor associated 43 000-dalton v1 protein did not react with any of the probes. A striking difference in labeling between T. marmorata and T. californica acetylcholine receptors occurred at the level of the alpha-subunit when the superficial PCI probe was used. An approximately 5-fold higher labeling of the alpha-subunit as compared to the beta-, gamma-, and delta-subunits was observed by using receptor-rich membranes from T. marmorata but not from T. californica. The same difference persisted after purification of the labeled receptors from the two species and was restricted to an 8000-dalton C-terminal tryptic peptide. The only mutation observed in this region of the complete alpha-subunit sequence of the two species is the substitution of cysteine-424 in T. marmorata by serine-424 in T. californica.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Interaction between cytochrome c and ubiquinone-cytochrome c oxidoreductase: a study with water-soluble carbodiimides.

The role of carboxyl groups on the interaction between ubiquinone-cytochrome c oxidoreductase (Complex III) and cytochrome c has been probed using the two water-soluble carbodiimides EDC (1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide) and CMC (1-cyclohexyl-3-(2-morpholinyl-4-ethyl) carbodiimide metho-p-toluensulphonate). The results suggest that: 1) carboxyl groups present on both cytochrome c1 and subunit VIII are modified. Some of these residues are shielded by cytochrome c. 2) The enzyme activity decreases during the carbodiimide treatment and the extent of inhibition is larger in the presence of cytochrome c. 3) Cytochrome c, equimolar with the enzyme, cross-links to cytochrome c1 and subunit VIII via the carbodiimide-activated carboxyl groups. The two subunits appear to be in contact in the isolated enzyme.

Animals↗
PubMed1983

Arrangement of subunit IV in beef heart cytochrome c oxidase probed by chemical labeling and protease digestion experiments.

The arrangement of subunit IV in beef heart cytochrome c oxidase has been explored by chemical labeling and protease digestion studies. This subunit has been purified from four samples of cytochrome c oxidase that had been reacted with N-(4-azido-2-nitrophenyl)-2-aminoethyl[35S]-sulfonate (NAP-taurine), diazobenzene[35S]sulfonate, 1-myristoyl-2-[12-[(4-azido-2-nitrophenyl)amino]lauroyl]-sn-glycero-3- [14C]phosphocholine (I), and 1-palmitoyl-2-(2-azido-4-nitrobenzoyl)-sn-glycero-3-[3H]phosphocholine (II), respectively. The labeled polypeptide was then fragmented by cyanogen bromide, at arginyl side chains with trypsin (after maleylation), and the distribution of the labeling within the sequence was analyzed. The N-terminal part of subunit IV (residues 1-71) was shown to be heavily labeled by water-soluble, lipid-insoluble reagents but not by the phospholipid derivatives. These latter reagents labeled only in the region of residues 62-122, containing the long hydrophobic and putative membrane-spanning stretch. Trypsin cleavage of native cytochrome c oxidase complex at pH 8.2 was shown to clip the first seven amino acids from subunit IV. This cleavage was found to occur in submitochondrial particles but not in mitochondria or mitoplasts. These results are interpreted to show that subunit IV is oriented with its N terminus on the matrix side of the mitochondrial inner membrane and spans the membrane with the extended sequence of hydrophobic lipid residues 79-98 buried in the bilayer.

Animals↗
PubMed1982

Different polypeptides of bovine heart cytochrome c oxidase are in contact with cytochrome c.

Two water-soluble carbodiimides, differing in molecular dimensions, have been used to characterize the cytochrome c binding site of bovine heart cytochrome c oxidase. Several polypeptide components of the enzyme contain acidic residues which are modified by these reagents. Carboxyl groups present in subunit II, VII and polypeptide c, are protected from modification when cytochrome c, equimolar to oxidase, is added and they can cross-link to the substrate once activated by the carbodiimide. Comparison of the modification patterns suggest that the most reactive residues are located on subunit II and VII, the former being also more exposed. The data obtained indicate that even though subunit II plays the major role in binding cytochrome c, at least two other lower Mr polypeptides contribute to the cytochrome c binding domain.

Animals↗
PubMed1982

Localization of lipid binding domain(s) on subunit II of beef heart cytochrome c oxidase.

Photoactivatable arylazido phospholipids (Bisson, R., and Montecucco, C. (1981) Biochem. J. 193, 757-763) have been used to study the arrangement in the membrane of beef heart cytochrome c oxidase subunit II. Fragmentation of the photocross-linked polypeptide showed that sequence 20-98, which contains two long stretches of uncharged amino acid residues (Steffens, G. J., and Buse, G. (1979) Hoppe-Seyler's Z. Physiol. Chem. 360, 613-619), is in contact with lipids. Edman degradation of the labeled peptide indicated that His 26, Thr 27 and Met 29 are involved in the interaction with the polar head region of the bilayer. These data have been used to propose a scheme for the folding of subunit II in the mitochondrial membrane.

Animals↗
PubMed1982

[Synthetic salmon calcitonin. Treatment of choice in Sudeck's disease].

56 cases of primary and post-traumatic Sudeck's disease, treated with Sandoz synthetic salmon calcitonine are reported. The results obtained suggest that this drug should be considered of choice in this type of pathology provided it is administered with the right, highish doses. 2 completely cured cases of stemming of bone cyst using the same product are also reported.

Calcitonin↗
PubMed1981

Membrane topology of beef-heart ubiquinone-cytochrome c reductase (complex III).

The membrane topology of ubiquinone-cytochrome c reductase (EC 1.10.2.2.) has been investigated with photoreactive lipid analogs (Bisson, R., and Montecucco, C. (1981) Biochem. J. 193, 757-763), both in its isolated form and when part of succinate-cytochrome c reductase (Complex II + III). These probes react specifically with those polypeptide chains exposed to lipids, thereby labeling them radioactively. Highly resolving gel electrophoretic conditions have been used to determine the patterns of labeling. Core protein I, cytochrome b, cytochrome c1, and polypeptides VI, VII, VIII, and IX contribute to the lipid-protein boundary of Complex III. Evidence that the interaction between Complex II and Complex III involves their hydrophobic domains is also presented.

Animals↗
PubMed1981

Inhibition of cytochrome c oxidase function by dicyclohexylcarbodiimide.

Dicyclohexylcarbodiimide (DCCD) reacted with beef heart cytochrome c oxidase in inhibit the proton-pumping function of this enzyme and to a lesser extent to inhibit electron transfer. The modification of cytochrome c oxidase in detergent dispersion or in vesicular membranes was in subunits II-IV. Labelling followed by fragmentation studies showed that there is one major site of modification in subunit III. DCCD was also incorporated into several sites in subunit II and at least one site of subunit IV. The major site in subunit III has a specificity for DCCD at least one order of magnitude greater than that of other sites (in subunits II and IV). Its modification could account for all of the observed effects of the reagent, at least for low concentrations of DCCD. Labelling of subunit II by DCCD was blocked by prior covalent attachment of arylazidocytochrome c, a cytochrome c derivative which binds to the high-affinity binding site for the substrate. The major site of DCCD binding in subunit III was sequenced. The label was found in glutamic acid 90 which is in a sequence of eight amino acids remarkably similar to the DCCD-binding site within the proteolipid protein of the mitochondrial ATP synthetase.

Amino Acid Sequence↗
PubMed1981

Binding of arylazidocytochrome c to yeast cytochrome c peroxidase.

Cytochrome c derivatives modified with a photoactivatable arylazido group in selected lysine residues were irradiated in the presence of cytochrome c peroxidase (EC 1.11.1.5). A derivative modified at lysine 13 was able to cross-link to the enzyme and inhibit electron transfer activity. Complete inhibition of cytochrome c peroxidase activity was obtained when 1 mol of cytochrome c was covalently bound per mol of cytochrome c peroxidase. Chemical cleavage of the covalent complex has been used for a preliminary characterization of the site of cross-linking of cytochrome c to cytochrome c peroxidase. This linkage site was localized to the NH2 terminal part of cytochrome c peroxidase including residues 1-51.

Amino Acids↗
PubMed1981

Photolabelling of membrane proteins with photoactive phospholipids.

Photoactive probes have been introduced recently to study the hydrophobic sector of integral membrane proteins. A simple procedure to synthesize a new series of highly radioactive aryl azido-phospholipids is presented. They effectively exchange with the boundary lipids and, on illumination, the cross-link to several membrane proteins with high efficiency. The procedure and analysis of labelling of ATPase from sarcoplasmic reticulum is reported as an example. The advantages in using these photoactive phospholipids are discussed together with some information obtained on their use.

Adenosine Triphosphatases↗
PubMed1981

Interaction of succinate--ubiquinone reductase (complex II) with (arylazido)phospholipids.

The interaction of purified succinate dehydrogenase and succinate--ubiquinone reductase (complex II) with lipids was explored by using two (arylazido)phospholipids, one with the reactive nitrene in the head-group region of the bilayer [1-palmitoyl-2-(2-azido-4-nitrobenzoyl)-sn-glycero-3-[3H]phosphocholine (PLII)] and one with the nitrene on the methyl terminus of one of the fatty acid chains [1-myristoyl-2-[12-[(2-azido-4-nitrophenyl)amino]lauroyl]-sn-glycero-3-[14C]phosphocholine (PLI)]. Protein was reacted with vesicles of egg lecithin containing radioactive (arylazido)-phospholipids and the covalent cross-linking of lipid and protein induced by irradiation under UV light. Purified succinate dehydrogenase was found to bind to lipid vesicles through both subunits as both were labeled by PLII. The smaller subunit was inserted into the interior of the bilayer and labeled by PLI. Complex II was found to interact with lipid vesicles, with the smaller subunit of succinate dehydrogenase, CII-3, and CII-4 all inserted into the interior of the bilayer. The large subunit of succinate dehydrogenase was found to be held above the bilayer in complex II and not labeled by either probe. Results are used to derive a picture of the arrangement of subunits in complex II and to evaluate the utility of (arylazido)-phospholipids in membrane studies.

Affinity Labels↗