Photolysis

The interactions between photosystem I and five charge mutants of plastocyanin from the cyanobacteriumPhormi-dium laminosumwere investigatedin vitro. The dependence of the overall rate constant of reaction,k2, on ionic strength was investigated using laser flash photolysis. The rate con-stant of the wild-type reaction increased with ionic strength, indicating repulsion between the reaction partners. Remov-inganegativechargeonplastocyanin(D44A) acceleratedthe reactionandmade it independentof ionic strength; removing a positive charge adjacent to D44 (K53A) had little effect....

10p tumor12 22-04-2013 41 4   Download

Neuroglobin (Ngb) and cytoglobin (Cygb), recent additions to the globin family, display a hexa-coordinated (bis-histidyl) heme in the absence of external ligands. Although these proteins have the classical globin fold they reveal a very high thermal stability with a melting temperature (Tm)of 100
C for Ngb and 95
C for Cygb. Moreover, flash photolysis experi-ments at high temperatures reveal that Ngb remains functional at 90
C

9p awards 06-04-2013 34 3   Download

The different effects of pH and NaCl on individual O2-binding properties ofaandbsubunits within liganded tetramer and dimer of human hemo-globin (HbA) were examined in a number of laser time-resolved spectro-scopic measurements. A previously proposed approach [Dzhagarov BM & Lepeshkevich SV (2004)Chem Phys Lett390, 59–64] was used to determine the extent of subunit dissociation rate constant difference and subunit affinity difference from a single flash photolysis experiment.

11p dell39 27-03-2013 50 4   Download

The reactions of the flavin semiquinone generated by laser-induced stepwise two-photon excitation of reduced flavin have been studied previously (El Hanine-Lmoumene C & Lindqvist L. (1997) Photochem Photobiol66, 591–595) using time-resolved spectroscopy. In the present work, we have used the same experimental procedure to study the flavin semiquinone in rat kidney long-chain hydroxy acid oxidase and in the flavodehydrogenase domain of flavocytochrome b2 FDH

9p mobifone23 18-01-2013 59 4   Download