Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Monoamine oxidase activity in platelets prepared from the blood of patients with iron-deficiency anaemia was significantly lowered when compared with that in platelets from normal subjects. 2. The Km values of the platelet enzyme for the substrates dopamine, 5-hydroxytryptamine, phenylethylamine and kynuramine were similar for the platelet enzyme from iron-deficient and normal groups. 3. Heat-in-activation studies showed that the platelet monoamine oxidase from iron-deficient subjects was more labile to this treatment, when compared with the platelet enzyme from normal subjects. 4. The sensitivity of platelet monoamine oxidase to the inhibitors, clorgyline and deprenil, was increased in iron-deficiency anaemia. 5. Binding studies with the 14C-binding irreversible monoamine oxidase inhibitor, deprenil, showed that the amount of enzyme capable of binding this inhibitor was lowered by 48% in platelets from iron-deficient patients when compared with platelets from normal subjects. 6. The results show that there is a lowered amount of active enzyme in platelets from iron-deficient subjects. It is suggested that iron is necessary either for the synthesis of monoamine oxidase apoenzyme or is a cofactor for an enzyme which attaches flavin-adenine dinucleotide covalently to the monoamine oxidase apoenzyme.
Clin Sci Mol Med 1976 Jun
PMID:Some properties of human platelet monoamine oxidase in iron-deficiency anaemia. 0 85

Various chemical, physical and geological observations indicate that smectite clays are probably the major components of the Martian soil. Satisfactory ground-based chemical simulation of the Viking biology experimental results was obtained with the smectite clays nontronite and montmorillonite when they contained iron and hydrogen as adsorbed ions. Radioactive gas was released from the medium solution used in the Viking Labeled Release (LR) experiment when interacted with the clays, at rates and quantities similar to those measured by Viking on Mars. Heating of the active clay (mixed with soluble salts) to 160 degrees C in CO2 atmosphere reduced the decomposition activity considerably, again, as was observed on Mars. The decomposition reaction in LR experiment is postulated to be iron-catalyzed formate decomposition on the clay surface. The main features of the Viking Pyrolytic Release (PR) experiment were also simulated recently (Hubbard, 1979) which the iron clays, including a relatively low '1st peak' and significant '2nd peak'. The accumulated observations on various Martian soil properties and the results of simulation experiments, thus indicate that smectite clays are major and active components of the Martian soil. It now appears that many of the results of the Viking biology experiments can be explained on the basis of their surface activity in catalysis and adsorption.
J Mol Evol 1979 Dec
PMID:Smectite clays in Mars soil: evidence for their presence and role in Viking biology experimental results. 4 7

The oxidation of essential serum proteins, albumin and gamma globulin, by the enzyme peroxidase can be partially inhibited by compounds, such as EDTA and 2,4-pentanedione, that complex with the iron ion in peroxidase. The importance of such inhibition lies in the circumstance that the oxidations in question might be a possible causative factor in tissue aging.
Mol Biol Rep 1977 Jun
PMID:Inhibition of oxidation by peroxidase of human serum proteins. 6 89

The interaction of nitrogenase with spin labels of four types have been studied. Conclusion about the presence of two SH-groups in the nitrogenase active site (one in Mo-Fe-protein and one in the Fe-protein) have been drawn from the correlation between the degree of inhibition of nitrogenfixing activity by the labels derived from p-Cl-Hg-benzoate and degree of binding of these labels to the nitrogenase molecule. Anaysis of EPR spectra of spin-labeled nitrogenase at 77 degrees K and at room temperature have shown that the labels bind to the free SH-groups and interact with iron containing center (ICC) of nitrogenase through the exchange mechanism. Distance between SH-group and ICC have been found to be 12 A. Spin labels derived from isocyanide have been bound directly to ICC in amount of 6--10 labels per one nitrogenase molecule. Due to the exchange interaction between these labels they give the singlet ESR spectra both at 77 degrees and at room temperature which is characteristic for the closely disposed labels. From this fact a conclusion have been drawn about the cluster structure of ICC. The labels derived from iodoacetamide ana maleimide bind SH- and NH2-groups of nitrogenase molecules. Analysis of temperature dependence of the effective rotational frequency of this labels have revealed a conformational transition in nitrogenase molecule at 19 degrees C, that has made it possible to explain the break in the Arrenius plots of enzyme activity.
Mol Biol (Mosk)
PMID:[Study of the nitrogenase from Azotobacter vinelandii by the method of spin labels]. 17 70

The sensitivity of the molybdenum-iron(MoFe)-protein of Clostridium pasteurianum nitrogenase toward oxidation has been studied by determining the enzymatic activity of this component after incubating it anaerobically in ferricyanide solutions of various oxidizing strengths (as measured by their oxidation potentials). It was found that the MoFe-protein remains active at potentials up to +350 mV (vs. standard hydrogen electrode) but becomes readily inactivated at more oxidizing potentials, after a lag period, depending on the potential level and temperature. Oxidative inactivation by ferricyanide results in the release of most of the Mo, Fe and S atoms from the protein which causes the loss of the absorption bands in the visible region. The metals and sulfur could be re-incorporated by incubation in a mixture containing thiol, sulfide, molybdate, and ferric iron. The EPR spectrum of the oxidatively inactivated MoFe-protein showed that both the high- and low-field signals are readily affected. Re-incorporation of the metals and sulfur into the "bleached" protein produced an EPR spectrum similar to that of the air-inactivated protein. Incubation of the Mo-Fe-protein with mersalyl abolished its enzymic activity. The difference spectrum before and after mersalyl treatment resembles that of the soluble spinach ferredoxin.
Mol Cell Biochem 1979 Jul 31
PMID:Oxidative inactivation of the molybdenum-iron-protein component of nitrogenase from clostridium pasteurianum. 22 73

A protein of molecular weight 78,000 daltons, missing in albomycin and phage ES18 resistant mutants, has been identified in the outer membrane of Salmonella typhimurium SL1027. Mutants with a tonB like resistance and over production of outer membrane proteins due to iron shortage were also isolated. The mutation which leads to the protein deficiency maps in the sid gene region, the mutation related to overproduction of proteins maps near trp. Although the S. typhimurium and the E. coli protein mediate translocation of the iron complex ferrichrome and the structurally analogous antibiotic albomycin through the outer membrane no cross-reactivity exists in binding the phages T5, T1 and ES18 or colicin M.
Mol Gen Genet 1977 Oct 20
PMID:Identification of the sid outer membrane receptor protein in Salmonella typhimurium SL1027. 33 32

Compounds were studied that inhibit the oxidative degradation of human serum albumin by peroxidase and the enzyme model, iron hydroxide. Differences between the two oxidants gave clues for the mechanism of inhibition. The inhibitors studied were inorganic anions, phosphate, sulfate, carbonate and molybdate; organic anions, decanoate and glycocholate; and the nonionic species, glycogen. Such inhibitors might be considered as adjuvants in senescence: by decreasing the rate of enzymic oxidation of essential body proteins, they would, in the course of aging, reduce some of the physiological changes occurring as a result of accumulation of degraded protein.
Mol Biol Rep 1979 Feb 15
PMID:Inhibitors of oxidative degradation of protein: gerontological implications. 44 Feb 99

The distance between fluorescein mercuric acetate (FMA), attached to the HS-group of Fe- and Mo-Fe-protein, and the nearest iron-sulphur cluster (ISC) was determined. For Fe-protein the distance was 18--20 A and for Mo-Fe-protein 12--14 A. The distance between Fe-protein FMA and the nearest Mo-protein ISC determined by complementation of the labelled Fe-protein and native Mo-Fe-protein was 14--16 A. The distance between MO-OFe-protein ISC and complement Fe-protein ISC was 18--20 A. A te-protein ISC permitted to suppose that the electron was transfered from Fe-protein ISC to Mo-Fe-protein ISC by the contact of the ISC or with the help of ATP molecule.
Mol Biol (Mosk)
PMID:[Estimation of the distance between the iron-sulfur cluster of Fe-protein and the nearest iron-sulfur cluster of Mo-Fe-protein of nitrogenase on the basis of the inductive-resonance theory of energy transfer]. 50 57

Several ground-based investigations have been carried out since the Viking biology results were received from Mars. Many of these have resulted in reasonable simulations of the Martian data, using as analogues of Mars either strong oxidants, UV-treated materials, iron-containing clays, or iron salts. The ambiguity between the GCMS experiment, in which no organic compounds were found on Mars, and the Labeled Release experiment, in which added organics were decomposed, may well be accounted for by these simulations.
J Mol Evol 1979 Dec
PMID:Simulation of the Viking biology experiments: an overview. 52 51

The chemical reactivity of several minerals thought to be present in Martian fines is tested with respect to gases known in the Martian atmosphere. In these experiments, liquid water is excluded from the system, environmental temperatures are maintained below 0 degrees C, and the solar illumination spectrum is stimulated in the visible and UV using a Xenon arc lamp. Reactions are detected by mass spectrometric analysis of the gas phase over solid samples. No reactions were detected for Mars nominal gas over sulfates, nitrates, chloride, nontronite clay, or magnetitie. Oxidation was not observed for basaltic glass, nontronite, and magnetite. However, experiments incorporating SO2 gas--an expected product of volcanism and intrusive volatile release--gave positive results. Displacement of CO2 by SO2 occurred in all four carbonates tested. These reactions are catalyzed by irradiation with the solar simulator. A calcium nitrate hydrate released NO2 in the presence of SO2. These results have implications for cycling of atmospheric CO2, H2O, and N2 through the regolith.
J Mol Evol 1979 Dec
PMID:Heterogeneous phase reactions of Martian volatiles with putative regolith minerals. 52 62


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