A complete resonance Raman excitation profile of the heme charge-transfer band known as band III is presented. The data obtained throughout the near-infrared region show preresonance with the Q-band, but the data also clearly show the enhancement of a number of modes in the spectral region of band III. Only nontotally symmetric modes are observed to have resonance enhancement in the band III re...

When rhodopsin in a gelatin film is dried, the rhodopsin chromophores orient primarily in the plane of the film. When the film is wetted, the chromophores disorient. These changes are reversible. When rhodopsin in a wet film. is bleached in the presence of hydroxylamine and redried, the retinal oxime which results is oriented more perpendicularly to the plane of the film. These orientations in ...

Met80 of cytochrome c (cyt c) has been shown to dissociate from its heme iron when cyt c interacts with cardiolipin (CL), which triggers the release of cyt c into the cytosol initiating apoptosis. We found that the mass of human cyt c increases by 16 Da in the Met80-Lys86 region by reaction with molecular oxygen in the presence of CL-containing liposomes and dithiothreitol (DTT). To investigate...

GTN (nitroglycerin; glycerol trinitrate) causes dilation of blood vessels via activation of nitric oxide (NO)-sensitive sGC (soluble guanylate cyclase), a heterodimeric haem protein that catalyses the conversion of GTP into cGMP. Activation of sGC by GTN requires enzymatic or non-enzymatic bioactivation of the nitrate. Based on insufficient NO release and lack of spectroscopic evidence for form...

The deduced amino acid sequence of an slr1923 gene of Synechocystis sp. PCC6803 is homologous to archaean F(420)H(2) dehydrogenase, which acts as a soluble subcomplex of reduced nicotinamide adenine dinucleotide dehydrogenase complex I. In this study, the gene was inactivated and characteristics of the mutant were analyzed. The mutant grew slower than the wild type under 100 microE m(-2) s(-1) ...

The effect of temperature on the electronic structure of cytochromes a and a3 has been determined at two different concentrations of the solubilizing detergent, N-dodecyl beta-D-maltoside. In each case, an incubation temperature of 40 degrees C resulted in a 20-30% increase in the 430-nm conformer of cytochrome a3 when compared with a 20 degrees C control, but the higher detergent concentration...

The newly synthesized 5,10,15,20-tetra[3-(3-trifluoromethyl)phenoxy]porphyrin, TTFMPP, has been characterized using mass spectroscopy, 1H-, 13C- and 19F-NMR, MALDI-TOF mass spectrometry, UV-Vis and fluorescence spectrophotometry, and cyclic voltammetry. The NMR confirmed the structure of the compound and the mass spectrum was in agreement with the proposed molecular formula. The UV-Vis absorpti...

Tobacco peroxidase (36 kDa, pI 3.5) exhibits unique catalytic and spectral properties that are modulated by pH, calcium and magnesium ions. It catalyses the oxidation of veratryl alcohol by hydrogen peroxide over a wide pH range (1.5-5.0) in the presence of these metal ions with a pH optimum of 1.8. This is the only example of a holoperoxidase described so far that is active and comparatively s...

The first dimeric catalase-peroxidase of eucaryotic origin, an intracellular hydroperoxidase from Penicillium simplicissimum which exhibited both catalase and peroxidase activities, has been isolated. The enzyme has an apparent molecular mass of about 170 kDa and is composed of two identical subunits. The purified protein has a pH optimum for catalase activity at 6.4 and for peroxidase at 5.4. ...

Action spectra for photoreactivation (light-induced recovery from ultraviolet radiation injury) of Escherichia coli B/r and Streptomyces griseus ATCC 3326 were determined. The spectral region explored was 365 to 700 mmicro. The action spectrum for S. griseus differed from that for E. coli, indicating that the chromophores absorbing reactivating energy in the two species were not the same. React...