Cytochrome c, A Membrane-Bound Enzyme

1976 ◽  
pp. 43-86 ◽  
Author(s):  
Jane Vanderkooi ◽  
Maria Erecińska
Keyword(s):  
Cytochrome C ◽  
Membrane Bound

scholarly journals Arrangement of the subunits in solubilized and membrane-bound cytochrome c oxidase from bovine heart.

1975 ◽  
Vol 250 (22) ◽  
pp. 8598-8603 ◽  
Author(s):  
GD Eytan ◽  
RC Carroll ◽  
G Schatz ◽  
E Racker
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Bovine Heart ◽  
Membrane Bound

scholarly journals How Lipids Mobilise Membrane-Bound Cytochrome C Seen by Solid-State NMR

2021 ◽  
Vol 120 (3) ◽  
pp. 284a
Author(s):  
Patrick C.A. van der Wel
Keyword(s):  
Solid State ◽  
Cytochrome C ◽  
Solid State Nmr ◽  
Membrane Bound

scholarly journals Structure of the copper sites in membrane-bound cytochrome c oxidase.

1987 ◽  
Vol 262 (7) ◽  
pp. 3160-3164
Author(s):  
L. Powers ◽  
B. Chance ◽  
Y.C. Ching ◽  
C.P. Lee
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Membrane Bound ◽  
Copper Sites

Characterization of the Metamitron Deaminating Enzyme Activity from Sugar Beet ( Beta vulgaris L.) Leaves

1979 ◽  
Vol 34 (11) ◽  
pp. 948-950 ◽  
Author(s):  
Carl Fedtke ◽  
Robert R. Schmidt
Keyword(s):  
Cytochrome C ◽  
Sugar Beet ◽  
Electron Donor ◽  
Nitrogen Atmosphere ◽  
Enzyme Preparations ◽  
Reducing Conditions ◽  
Trade Name ◽  
Membrane Bound

Abstract The enzymatic activity from sugar beet leaves which is responsible for the detoxification of the herbicide metamitron (4-amino-4,5-dihydro-3-methyl-6-phenyl-1, 2, 4-triazin-5-one, trade name Goltix®) has been characterized in vitro. The detoxification occurs by rapid deamination in vivo as well as in vitro. However, the deamination in vitro is only maximal under reducing conditions, i. e. with an electron donor and in a nitrogen atmosphere. The electron donor may be cystein, glutathione, dithionite or ascorbate. The enzymatic deamination further requires the addition of cytochrome c and a “supernatant factor”, which may be replaced by FMN, FAD or DCPIP. However, in the presence of FMN or DCPIP cytochrome c is not essential but only stimulatory. The partic­ulate as well as the soluble metamitron deaminating enzyme preparations obtained take up oxygen when supplied with cysteine and FMN. The particulate enzyme appears in the peroxysome-fraction. It is therefore suggested, that the enzymatic deamination of metamitron in sugar beet leaves is mediated by a proxisomal membrane bound electron transport system which alternatively may reduce oxygen or metamitron (deaminating).

scholarly journals Activation of Membrane-associated Procaspase-3 Is Regulated by Bcl-2

1999 ◽  
Vol 144 (5) ◽  
pp. 915-926 ◽  
Author(s):  
Joseph F. Krebs ◽  
Robert C. Armstrong ◽  
Anu Srinivasan ◽  
Teresa Aja ◽  
Angela M. Wong ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Caspase 3 ◽  
Caspase Activity ◽  
Intracellular Membrane ◽  
Caspase Activation ◽  
Intracellular Membranes ◽  
Membrane Bound ◽  
Spontaneous Activation ◽  
Active Caspase

The mechanism by which membrane-bound Bcl-2 inhibits the activation of cytoplasmic procaspases is unknown. Here we characterize an intracellular, membrane-associated form of procaspase-3 whose activation is controlled by Bcl-2. Heavy membranes isolated from control cells contained a spontaneously activatable caspase-3 zymogen. In contrast, in Bcl-2 overexpressing cells, although the caspase-3 zymogen was still associated with heavy membranes, its spontaneous activation was blocked. However, Bcl-2 expression had little effect on the levels of cytoplasmic caspase activity in unstimulated cells. Furthermore, the membrane-associated caspase-3 differed from cytosolic caspase-3 in its responsiveness to activation by exogenous cytochrome c. Our results demonstrate that intracellular membranes can generate active caspase-3 by a Bcl-2–inhibitable mechanism, and that control of caspase activation in membranes is distinct from that observed in the cytoplasm. These data suggest that Bcl-2 may control cytoplasmic events in part by blocking the activation of membrane-associated procaspases.

Oxyfluorfen and Lipid Peroxidation: Protein Damage as a Phytotoxic Consequence

Weed Science ◽  
1985 ◽  
Vol 33 (6) ◽  
pp. 766-770 ◽  
Author(s):  
Karl J. Kunert ◽  
Carmen Homrighausen ◽  
Herbert Böhme ◽  
Peter Böger
Keyword(s):  
Lipid Peroxidation ◽  
Cytochrome C ◽  
Diphenyl Ether ◽  
Photosynthetic Electron Transport ◽  
Water Soluble ◽  
Cytochrome F ◽  
Protein Damage ◽  
Protein Loss ◽  
Membrane Bound

Protein damage, as a primary phytotoxic consequence of in vivo lipid peroxidation, induced by the diphenyl ether herbicide oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene] at a concentration of 10 μM, was measured with the green algaScenedesmus acutus. In the light, water-soluble proteins are destroyed by a herbicide-induced peroxidation process that can be detected by production of fluorescent products and loss of specific amino acid residues of proteins. The water-soluble cytochrome c-553 and the membrane-bound cytochrome f-553, components of the photosynthetic electron transport, were specifically used as sensitive markers for protein damage, measured as decrease of redox reactions of the cytochromes. Under peroxidizing conditions, destruction of the algal cytochrome c is significantly higher than destruction of membrane-bound components, such as cytochrome f and chlorophyll. Protection against protein loss is achieved by the nonbiological antioxidant ethoxyquin (1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline) or the photosynthesis inhibitor diuron [N′-(3,4-dichlorophenyl)-N,N-dimethylurea].

scholarly journals Transcriptional control and essential roles of the Escherichia coli ccm gene products in formate-dependent nitrite reduction and cytochrome c synthesis

1998 ◽  
Vol 334 (2) ◽  
pp. 355-365 ◽  
Author(s):  
Sutipa TANAPONGPIPAT ◽  
Eleanor REID ◽  
Jeffrey A. COLE ◽  
Helen CROOKE
Keyword(s):  
Escherichia Coli ◽  
Cytochrome C ◽  
Transcriptional Control ◽  
Regulatory System ◽  
Nitrite Reduction ◽  
Anaerobic Growth ◽  
Current View ◽  
Fnr Protein ◽  
Genes Encoding ◽  
Membrane Bound

The eight ccm genes located at minute 47 on the Escherichia coli chromosome, in the order ccmABCDEFGH, encode homologues of proteins which are essential for cytochrome c assembly in other bacteria. The ccm genes are immediately downstream from the napFDAGHBC genes encoding a periplasmic nitrate reductase. CcmH was previously shown to be essential for cytochrome c assembly. Deletion analysis and a two-plasmid strategy have now been used to demonstrate that CcmA, B, D, E, F and G are also essential for cytochrome c assembly, and hence for cytochrome-c-dependent nitrite reduction. The ccm genes are transcribed from a ccmA promoter located within the adjacent gene, napC, which is the structural gene for a 24 kDa membrane-bound c-type cytochrome, NapC. Transcription from this ccmA promoter is induced approximately 5-fold during anaerobic growth, independently of a functional Fnr protein: it is also not regulated by the ArcB–ArcA two-component regulatory system. The ccmA promoter is an example of the ‘extended -10 sequence ’ group of promoters with a TGX motif immediately upstream of the -10 sequence. Mutagenesis of the TG motif to TC, CT or CC resulted in loss of about 50% of the promoter activity. A weak second promoter is suggested to permit transcription of the downstream ccmEFGH genes in the absence of transcription readthrough from the upstream napF and ccmA promoters. The results are consistent with, but do not prove, the current view that CcmA, B, C and D are part of an essential haem transport mechanism, that CcmE, F and H are required for covalent haem attachment to cysteine-histidine motifs in cytochrome c apoproteins in the periplasm, and that CcmG is required for the reduction of cysteine residues on apocytochromes c in preparation for haem ligation.

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