1,720,976 research outputs found
La Nuova Galles (del Sud) la terra Vittoria (Australia Felice) e l'isola di Diemen [cartographic material].
No full textMap of southeastern Australia showing Tasmania, Victoria and New South Wales extending into Queensland. Relief shown by hachures.; In upper left margin: Marmocchi.; In lower right margin: G. Bonatti inc. Torino.; Prime meridian: Ferro.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.map-rm3698
Modificazioni chimiche dellelisine della superossido dismutasi in relazione alla attività catalitica
No full textSuccinylated copper, zinc superoxide dismutase. A novel approach to the problem of active subunits
No full textBovine erythrocyte superoxide dismutase (BESOD) has been extensively succinylated with succinic anhydride. Succinylated BESOD has an identical electron paramagnetic resonance (EPR) spectrum but only 10% as much activity as the native enzyme, showing that an increase of the negative charge of the protein surface lowers the activity without alteration of the active site structure. On the other hand, sodium dodecyl sulfate (NaDodSO4)-polyacrylamide gel electrophoresis indicates that interaction between subunits is strongly weakened by succinylation. NaDodSO4 has no effect on either the activity or EPR spectrum of the protein. BESOD was immobilized by coupling to a Sepharose matrix with no alteration of the EPR spectrum. Succinylation of the immobilized protein led to detachment from the gel of approximately 50% of the molecules, as estimated by parallel EPR measurements of the gel and activity determinations on the eluate. It is concluded the succinylation leads to dissociation of BESOD into nondenatured subunits, having lower activity than the native protein possibly because of charge effects on the enzyme-O2-interaction
Baker's yeast cytosine deaminase. Some enzymic properties and allosteric inhibition by nucleosides and nucleotides
No full textAdenosine deaminase from Saccharomyces cerevisiae: kinetics and interaction with transition and ground state inhibitors
No full textA comparative study of bovine, porcine and yeast superoxide dismutases
No full textThe Cu,Zn superoxide dismutases from bovine and porcine erythrocytes and from yeast have been investigated with the aim to identify structural differences in relation to possible functional variability in this highly homologous class of protein. The isoelectric points of the bovine, porcine and yeast proteins were found to be 4.8, 5.8 and 4.5 respectively. According to these values the net protein charge, as evaluated by gel electrophoresis, varied more significantly for the porcine protein than for the other two proteins tested. The catalytic constants were found to be higher at pH = 7.6 than at pH 10.0 for all the three enzymes. This relative increase was much more pronounced in the case of the porcine enzyme. The KM value at pH = 10.0 was also significantly higher for the porcine enzyme. Since the spectroscopic properties of the active sites were identical for the three proteins, these results point to modulation effects by positively charged amino acid residues on the superoxide dismutase activity of these proteins, in a way that the resultant net charge of the protein seems to be as important as specific residues
Purificazione e caratterizzazione della superossido dismutasi a rame e zinco da eritrociti di maiale
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