Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in distal pocket of peroxidases have successfully been introduced into that of the VHb. Fifteen-fold increase in catalytic constant (k(cat)) was obtained in P54R variant, which was presumably attributable to the lower rigidity and higher hydrophilicity of distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either H(2)O(2) or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring T29H mutation apparently demonstrated the spectral shift in both ferric and ferrous forms (406-408 to 411 nm and 432 to 424-425 nm, respectively). All VHb proteins in ferrous state had lambda(soret) peak at approximately 419 nm following the carbon monoxide (CO) binding. Expression of P54R mutant mediated the down-regulation of iron superoxide dismutase (FeSOD) as identified by 2-dimensional gel electrophoresis (2-DE) and peptide mass fingerprinting (PMF). According to the high peroxidase activity of P54R, it could effectively eliminate autoxidation-derived H2O2, which is a cause of heme degradation and iron release. This decreased the iron availability and consequently reduced the formation of Fe(2+)-ferric uptake regulator protein (Fe(2+)-Fur), an inducer of FeSOD expression.
Propose and investigate two novel heuristic approaches to reduce the
Computation time considerably while attaining high-quality solutions. We
Introduce a family of heuristic cuts based on the concept of 'adjacent beams'
And a beam elimination scheme based on the contribution of each beam to deliv...
We demonstrate that UBXN-2, a substrate adaptor of the AAA ATPase Cdc48/p97, is required to coordinate centrosome maturation timing with mitosis. In UBXN-2-depleted Caenorhabditis elegans embryos, centrosomes recruited more AIR-1 (Aurora A), matured precociously, and alignment of the mitotic spindle...
Pubget Updates sends you emails when Pubget finds new papers that match your search. Use Pubget Updates to get the latest articles for your specialty, written by a colleague, or published by your favorite journals.