Oxidized cytochrome c oxidase in a carbon monoxide atmosphere slowly becomes reduced as shown by changes in its visible spectra and its reactivity toward oxygen. The "auto-reduction" of cytochrome c oxidase by this procedure has been used to prepare mixed valence hybrids. We have found that this process is a general phenomenon for oxygen-binding heme proteins, and even for isolated hemin in bas...

The effect of Annona squamosa, Lawsonia inermis and their combination with other herbal molluscicides were studied on different enzyme activity in the nervous tissue of Lymnaea acuminata. Twenty-Four hour in vivo exposure to 40% and 80% of 24 h LC50 of plant derived molluscicides and their combination with other molluscicides such as Cedrus deodara, Azadirachta indica oil, Allium sativum, Polia...

Methyl sterol oxidase of microsomal synthesis of cholesterol from lanosterol is a mixed-function oxidase that is dependent upon reduced pyridine nucleotide. The methyl sterol oxidase, as well as NADH-cytochrome c reductase, in intact rat liver microsomes are inhibited by anti-cytochrome b5 immunoglobulin, but NADPH-cytochrome c reductase is not affected. There is a decreased time lag prior to o...

Available information on the molecular mechanisms by which nitric oxide (NO) controls the activity of the respiratory enzyme (cytochrome-c-oxidase) is reviewed. We report that, depending on absolute electron flux, NO at physiological concentrations reversibly inhibits cytochrome-c-oxidase by two alternative reaction pathways, yielding either a nitrosyl- or a nitrite-heme a3 derivative. We addre...

40 Echinococcus isolates from sheep and cattle in Southern Brazil were genetically analysed in order to obtain further data on the presence of different taxa of the Echinococcus granulosus complex. Differentiation was done using a PCR technique and sequencing of mitochondrial cytochrome c oxidase subunit 1 (CO1). Most samples (38) could be allocated to the sheep strain (G1) of E. granulosus, wh...

Two regions of mitochondrial (mt) DNA, cytochrome c oxidase subunit 1 (COI) and 16S rRNA, were sequenced in nine species of Betta from Thailand and Indonesia. Most species showed little intraspecific COI variation (adjusted mean = 0.48%) including the putative species Betta sp. Mahachai, but one species (Betta smaragdina) included three lineages showing much greater divergence (7.03-13.48%) tha...

Strains of the yeast Saccharomyces cerevisiae disrupted in YCOX4, the nuclear gene encoding cytochrome c oxidase subunit IV, do not assemble a functional or spectrally visible oxidase. We report the characterization of a yeast strain, RM1, expressing a mutated YCOX4 gene which is temperature sensitive for respiration at 37 "C, but incorporates cytochrome aas over all growth temperatures. The mu...

UNLABELLED Mycobacterium tuberculosis depends on aerobic respiration for growth and utilizes an aa3-type cytochrome c oxidase for terminal electron transfer. Cytochrome c maturation in bacteria requires covalent attachment of heme to apocytochrome c, which occurs outside the cytoplasmic membrane. We demonstrate that in M. tuberculosis the thioredoxin-like protein Rv3673c, which we named CcsX, i...