Recent studies on the chemical nature of cytochrome oxidase (cytochrome c :02 oxidoreductase, EC 1.9.3.1) have been concerned largely with the structure of its iron-porphyrin prosthetic group (cj. (l)), the importance of copper as an integral component of the enzyme (e.g. (2-5)), and the possible role of a lipid factor (e.g. (6-8)). By contrast, little work has been done on the nature of the fu...

The properties of plant purple acid phosphatases (PAPs), metallophosphoesterases present in some bacteria, plants and animals are reviewed. All members of this group contain a characteristic set of seven amino-acid residues involved in metal ligation. Animal PAPs contain a binuclear metallic center composed of two irons, whereas in plant PAPs one iron ion is joined by zinc or manganese ion. Amo...

BACKGROUND The 'Rieske' iron-sulfur protein is the primary electron acceptor during hydroquinone oxidation in cytochrome bc complexes. The spectroscopic and electrochemical properties of the 'Rieske' [2Fe-2S] cluster differ significantly from those of other iron-sulfur clusters. A 129-residue water soluble fragment containing the intact [2Fe-2S] cluster was isolated following proteolytic digest...

The higher affinity of Cd(2+) for sulfur compounds than for nitrogen and oxygen led to the theoretical consideration that cadmium toxicity should result mainly from the binding of Cd(2+) to sulfide, thiol groups, and sulfur-rich complex compounds rather than from Cd(2+) replacement of transition-metal cations from nitrogen- or oxygen-rich biological compounds. This hypothesis was tested by usin...

BACKGROUND Disulfide-linked oligodeoxyribonucleotide (ODN) liposomes were formulated and evaluated for the delivery of antisense ODN G3139 in KB human oral carcinoma cells. MATERIALS AND METHODS Liposomes composed of 1,2-di-(9Z-octadecenoyl)-3-trimethylammo-nium-propane (DOTAP)/egg phosphatidylcholine/alpha-tocopheryl polyethylene glycol 1000 succinate were incorporated with hydrophobized dis...

Objective: The main objective of this study was to compare the effects minimal and high gas flow-controlled hypotension applications on IMA thiol/disulfide balance, which are indicators oxidative stress.Methods: Patients undergoing elective tympanoplasty were randomized two groups as minimal-flow high-flow anesthesia groups. Minimal flow performed with 5L/min fresh reduced 0.4 L/min. High admin...

We report a detailed classification of disulfide patterns to further understand the role of disulfides in protein structure and function. The classification is applied to a unique searchable database of disulfide patterns derived from the SwissProt and Pfam databases. The disulfide database contains seven times the number of publicly available disulfide annotations. Each disulfide pattern in th...

Friedreich's ataxia is a neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin. The main phenotypic features of frataxin-deficient human and yeast cells include iron accumulation in mitochondria, iron-sulphur cluster defects and high sensitivity to oxidative stress. Glutathione is a major protective agent against oxidative damage and glutathione-related sy...

objective(s): carbon nanotube (cnt) has been widely applied at molecular and cellular levels due to its exceptional properties. studies based on conjugation of cnts with biological molecules indicated that biological activity is preserved. polyethylenimine (pei) is explored in designing novel gene delivery vectors due to its ability to condense plasmid dna through electrostatic attraction. in t...