Mostrando 13-24 de 60 artigos, teses e dissertações.
13. Structure of carboxymyoglobin in crystals and in solution.
The configuration of the heme-carbonyl group upon binding of carbon monoxide to sperm whale myoglobin (Mb) in crystals is evaluated on the basis of infrared spectroscopic methods. Multiplets of the totally symmetric C-O stretching mode are observed for the heme-bound ligand near 1933, 1944, and 1967 cm-1, corresponding to three different heme-carbonyl confor
14. Magnetic circular dichroism of ferrous carbonyl adducts of cytochromes P-450 and P-420 and their synthetic models: further evidence for mercaptide as the fifth ligand to iron.
Absorption and magnetic circular dichroism (MCD) spectra have been obtained for the ferrous carbonyl adducts of cytochromes P-450 and P-420 as well as synthetic model systems. Ferrous porphyrins with sodium methyl mercaptide and CO in benzene give MCD and absorption spectra which are almost identical to those of the natural enzyme, indicating that in P-450 a
15. IN VITRO EFFECTS OF C-REACTIVE PROTEIN ON PHAGOCYTOSIS
Hokama, Y. (University of California, Los Angeles), Monroe K. Coleman, and Richard F. Riley. In vitro effects of C-reactive protein on phagocytosis. J. Bacteriol. 83:1017–1024. 1962. Carbonyl iron spherules, Diplococcus pneumoniae types IIs and XXVIIs, and Serratia marcescens were phagocytosed more rapidly and in greater numbers by leukocytes of normal hum
16. Experimental liver cirrhosis induced by alcohol and iron.
To determine if alcoholic liver fibrogenesis is exacerbated by dietary iron supplementation, carbonyl iron (0.25% wt/vol) was intragastrically infused with or without ethanol to rats for 16 wk. Carbonyl iron had no effect on blood alcohol concentration, hepatic biochemical measurements, or liver histology in control animals. In both ethanol-fed and control r
17. Initial characterization of the ferric iron transport system of Corynebacterium diphtheriae.
Transport of ferric iron into Corynebacterium diphtheriae C7(beta) was shown to occur by a high-affinity, active transport system. Optimal rates were at pH 6.8 and 40 degrees C. Strong inhibition of uptake by carbonyl cyanide m-chlorophenylhydrazone was consistent with the electrochemical proton gradient as the major energy source for iron transport, and inh
18. Biliary excretion of iron from hepatocyte lysosomes in the rat. A major excretory pathway in experimental iron overload.
In these experiments, we assessed the role of hepatocyte lysosomes in biliary excretion of iron. We loaded rats with iron by feeding 2% carbonyl iron and collected bile for 24 h via bile fistulae from iron-loaded and control rats. In additional rats, bile was collected before and after the administration of colchicine. Rats were then killed and their livers
19. Malondialdehyde and 4-hydroxynonenal protein adducts in plasma and liver of rats with iron overload.
In hepatic iron overload, iron-catalyzed lipid peroxidation has been implicated in the mechanisms of hepatocellular injury. Lipid peroxidation may produce reactive aldehydes such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), which may form aldehyde-protein adducts. We investigated whether lipid peroxidation occurred in rats fed a diet containing 3%
20. Iron-carbonyl bond geometries of carboxymyoglobin and carboxyhemoglobin in solution determined by picosecond time-resolved infrared spectroscopy.
The iron-carbonyl geometries in carboxymyoglobin (MbCO) and carboxyhemoglobin (HbCO) in ambient temperature solution have been investigated using picosecond time-resolved infrared spectroscopy. Polarized infrared and visible beams were used to monitor the change in infrared absorbance of the bound CO stretch bands on photodissociation of the ligand. The rati
21. Iron mediates production of a neutrophil chemoattractant by rat hepatocytes metabolizing ethanol.
Ethanol metabolism in hepatocytes is accompanied by release of a potent lipid chemoattractant for neutrophils. Production of the factor may initiate the inflammation associated with alcoholic hepatitis. In previous studies with a cytosol system from liver, production was blocked by iron chelators as well as by catalase and superoxide dismutase, suggesting th
22. Iron respiration-driven proton translocation in aerobic bacteria.
Washed cell suspensions of Aquaspirillum magnetotacticum MS-1, A. itersonii E12639, Bacillus subtilis 6633, and Escherichia coli CSH27 translocated protons in response to the added oxidant O2 or NO3-, with triphenylmethylphosphonium bromide as the permeant ion. Iron respiration-driven proton translocation was observed in A. magnetotacticum MS-1, B. subtilis,
23. Respiration-linked proton translocation coupled to anaerobic reduction of manganese(IV) and iron(III) in Shewanella putrefaciens MR-1.
An oxidant pulse technique, with lactate as the electron donor, was used to study respiration-linked proton translocation in the manganese- and iron-reducing bacterium Shewanella putrefaciens MR-1. Cells grown anaerobically with fumarate or nitrate as the electron acceptor translocated protons in response to manganese (IV), fumarate, or oxygen. Cells grown a
24. Structure and chemistry of a metal cluster with a four-coordinate carbide carbon atom
Molecular metal clusters with carbide carbon atoms of low coordination number have been prepared; they are the anionic [HFe4C(CO)12-] and [Fe4C(CO)122-] clusters. An x-ray crystallographic analysis of a tetraaminozinc salt of the latter has established a butterfly array of iron atoms with the carbide carbon atom centered above the wings of the Fe4 core. Each