113 research outputs found
Circular Dichroism of Partially Purified Cytochrome P450 from Rabbit Liver Microsomes
The heme-related circular dichroic bands of solubilized cytochrome
P450 from rabbit liver microsomes and some of its liganded
derivatives were measured in the Soret region. All P450 derivatives
exhibit negative circular dichroic bands in the region of the Soret
absorption. The wavelengths of the dichroic bands and their ellipticities
vary with ligand substitution and the oxidation state of the
iron. The results are compared with CD-data from other hemoproteins
and discussed with respect to stereochemical conclusions
concerning the geometry and the physicochemical character of the
vicinity of the heme group with regard to results obtained from
other studies
Evidence of the Existence of a High Spin Low Spin Equilibrium in Liver Microsomal Cytochrome P450, and its Role in the Enzymatic Mechanism
In rabbit liver microsomal cytochrome P450 a high spin (S =
= 5/2) low spin (S = 1/2) equilibrium has been proved to exist by
recording temperature difference spectra in the Soret and in the
visible region of the absorption spectrum of solubilized cytochrome
P450. In the presence of type II substrates the predominantly low
spin state of cytochrome P450 is maintained, only a very small shift
to lower spin is observed. Ligands of the heme iron, such as cyanide
and imidazole, pr9duce a pure low spin state and therefore in the
presence of these ligands no temperature difference spectra can be
obtained. In the presence of type I substrate, however, the spin
equilibrium is shifted to the high spin state. The extent of this
shift (1) depends on specific properties of the substrate and (2) it is
generally relatively small, up to about 80/o in the case of substrates
investigated so far
Binding behaviour of substrate analogous spin-labelled n-alkylamines in liver microsomal cytochrome P-450
Evidence of the Existence of a High Spin Low Spin Equilibrium in Liver Microsomal Cytochrome P450, and its Role in the Enzymatic Mechanism
In rabbit liver microsomal cytochrome P450 a high spin (S =
= 5/2) low spin (S = 1/2) equilibrium has been proved to exist by
recording temperature difference spectra in the Soret and in the
visible region of the absorption spectrum of solubilized cytochrome
P450. In the presence of type II substrates the predominantly low
spin state of cytochrome P450 is maintained, only a very small shift
to lower spin is observed. Ligands of the heme iron, such as cyanide
and imidazole, pr9duce a pure low spin state and therefore in the
presence of these ligands no temperature difference spectra can be
obtained. In the presence of type I substrate, however, the spin
equilibrium is shifted to the high spin state. The extent of this
shift (1) depends on specific properties of the substrate and (2) it is
generally relatively small, up to about 80/o in the case of substrates
investigated so far
Deposition and spectral performance of an inhomogeneous broadband wide-angular antireflective coating
The gradient index coatings and optical filters based on them are a challenge for fabrication. In a round-robin experiment basically the same hybrid antireflection coating for the visible spectral region has been deposited with three different techniques: electron beam evaporation, ion beam sputtering and radio frequency magnetron-sputtering. Spectral performances of such one-side and both-side coated samples have been compared with corresponding theoretical spectra of the designed profile. Also, reproducibility of each process is checked
Circular Dichroism of Partially Purified Cytochrome P450 from Rabbit Liver Microsomes
The heme-related circular dichroic bands of solubilized cytochrome
P450 from rabbit liver microsomes and some of its liganded
derivatives were measured in the Soret region. All P450 derivatives
exhibit negative circular dichroic bands in the region of the Soret
absorption. The wavelengths of the dichroic bands and their ellipticities
vary with ligand substitution and the oxidation state of the
iron. The results are compared with CD-data from other hemoproteins
and discussed with respect to stereochemical conclusions
concerning the geometry and the physicochemical character of the
vicinity of the heme group with regard to results obtained from
other studies
Effective medium theories for composite optical materials in spectral ranges of weak absorption: the case of Nb 2
Two Steps Forward - One Step Back? Evaluating Contradicting Child Care Policies in Germany
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