scholarly journals The kinetics and thermodynamics of the reaction of solid-state fully reduced membrane-bound cytochrome oxidase with carbon monoxide as studied by dual-wavelength multichannel spectroscopy and flash photolysis

1979 ◽  
Vol 179 (1) ◽  
pp. i3-i5
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Cytochrome Oxidase ◽  
Flash Photolysis ◽  
Dual Wavelength ◽  
Kinetics And Thermodynamics ◽  
Membrane Bound

scholarly journals The kinetics and thermodynamics of the reaction of solid-state fully reduced membrane-bound cytochrome oxidase with carbon monoxide as studied by dual-wavelength multichannel spectroscopy and flash photolysis

1978 ◽  
Vol 175 (2) ◽  
pp. 709-725 ◽  
Author(s):  
G M Clore ◽  
E M Chance
Keyword(s):  
Solid State ◽  
Cytochrome Oxidase ◽  
Flash Photolysis ◽  
Linear Optimization ◽  
Dual Wavelength ◽  
Mechanism Of Reaction ◽  
Sequential Mechanism ◽  
Membrane Bound ◽  
Good Determination

1. The results of non-linear optimization studies on the mechanism of reaction of solid-state fully reduced membrane-bound cytochrome oxidase with CO over the 178–203 K range are presented. The analysis is carried out on data obtained by dual-wavelength multichannel spectroscopy at three wavelength pairs (444–463 nm, 590–630 nm and 608–630 nm), which yield three distinct progress curves. The only model that satisfies the triple requirement of a standard deviation within the standard error of the data, a random distribution of residuals and good determination of the optimized parameters is a two-species sequential mechanism: flash photolysis yields unliganded cytochrome oxidase and free CO, which then recombine to form species Ic; Ic is then converted into species IIc, which is identical with the cytochrome oxidase-CO complex existing before flash photolysis. All the thermodynamic parameters describing this model are calculated. 2. On the basis of the data obtained from this paper, together with data from potentiometric studies, magnetic susceptibility measurements and i.r. spectroscopy, the chemical identity of the species is suggested.

A flash-photolysis study of the reactions of acaa 3-ttype cytochrome oxidase with dioxygen and carbon monoxide

1996 ◽  
Vol 28 (6) ◽  
pp. 495-501 ◽  
Author(s):  
Shun Hirota ◽  
Margareta Svensson-Ek ◽  
Pia Ädelroth ◽  
Nobuhito Sone ◽  
Thomas Nilsson ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Cytochrome Oxidase ◽  
Flash Photolysis

A Dual-Wavelength Electrochromic Film Based on Pt(II) Complex for Optical Modulation at Telecommunication Wavelength and Dark Solid-State Display Device

2021 ◽  
Author(s):  
Qiaozhen Pi ◽  
Dongqin Bi ◽  
dongfang qiu ◽  
Hongwei Wang ◽  
Xinfeng Cheng ◽  
...  
Keyword(s):  
Solid State ◽  
Dual Wavelength ◽  
Optical Modulation ◽  
Display Device ◽  
Redox Behaviour ◽  
Diffusion Controlled ◽  
Telecommunication Wavelength

A cyclometalated platinum phenylacetylide [(L)Pt(C≡C-ph)] {L = 4-[p-(diphenylamino)phenyl]-6-phenyl-2,2’-bipyridine} has been successfully synthesized and characterized. And its oxidative electropolymerization film with a non-diffusion controlled redox behaviour and an inverse dependence of...

Bis(1-phenyl-1-propyne) complexes of tungsten(II): crystal structures of [WI2(CO)(NCR)(η2-MeC2Ph)2] (R = Me, Et, or Ph)

2001 ◽  
Vol 79 (3) ◽  
pp. 263-271
Author(s):  
Paul K Baker ◽  
Michael GB Drew ◽  
Deborah S Evans
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Crystal Structures ◽  
Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyne Complexes ◽  
First Time

Reaction of [WI2(CO)3(NCMe)2] with two equivalents of 1-phenyl-1-propyne (MeC2Ph) in CH2Cl2, and in the absence of light, gave the bis(1-phenyl-1-propyne) complex [WI2(CO)(NCMe)(η2-MeC2Ph)2] (1) in 77% yield. Treatment of equimolar quantities of 1 and NCR (R = Et, i-Pr, t-Bu, Ph) in CH2Cl2 afforded the nitrile-exchanged products, [WI2(CO)(NCR)(η2-MeC2Ph)2] (2-5) (R = Et (2), i-Pr (3), t-Bu (4), Ph (5)). Complexes 1, 2, and 5 were structurally characterized by X-ray crystallography. All three structures have the same pseudo-octahedral geometry, with the equatorial sites being occupied by cis and parallel alkyne groups, which are trans to the cis-iodo groups. The trans carbon monoxide and acetonitrile ligands occupy the axial sites. In structures 1 and 2, the methyl and phenyl substituents of the 1-phenyl-1-propyne ligands are cis to each other, whereas for the bulkier NCPh complex (5), the methyl and phenyl groups are trans to one another. This is the first time that this arrangement has been observed in the solid state in bis(alkyne) complexes of this type.Key words: bis(1-phenyl-1-propyne), carbonyl, nitrile, diiodo, tungsten(II), crystal structures.

Thermal effects of diode-end-pumped dual-wavelength solid-state lasers with coaxially arranged dual laser crystals

2021 ◽  
Author(s):  
Yizhe Zheng ◽  
Kai Zhong ◽  
Kefei Liu ◽  
Hongzhan Qiao ◽  
Xianzhong Zhang ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Effects ◽  
Dual Wavelength ◽  
Solid State Lasers ◽  
Laser Crystals ◽  
Dual Laser

The heterotrimeric Gi(3) protein acts in slow but not in fast exocytosis of rat melanotrophs

1999 ◽  
Vol 112 (22) ◽  
pp. 4143-4150 ◽  
Author(s):  
M. Kreft ◽  
S. Gasman ◽  
S. Chasserot-Golaz ◽  
V. Kuster ◽  
M. Rupnik ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
G Proteins ◽  
Flash Photolysis ◽  
Secretory Granules ◽  
Secretory Activity ◽  
Α Subunit ◽  
Capacitance Measurements ◽  
Regulated Secretion ◽  
Kinetic Component ◽  
Membrane Bound

Besides having a role in signal transduction some trimeric G-proteins may be involved in a late stage of exocytosis. Using immunocytochemistry and confocal microscopy we found that Gi(3)-protein resides mainly in the plasma membrane, whereas Gi(1/2-)protein is preferentially associated with secretory granules. To study the function of trimeric Gi(3)- and Gi(1/2)-proteins, secretory responses in single rat melanotrophs were monitored by patch-clamp membrane capacitance measurements. We report here that mastoparan, an activator of trimeric G-proteins, enhances calcium-induced secretory activity in rat melanotrophs. The introduction of synthetic peptides corresponding to the C-terminal domain of the (α)-subunit of Gi(3)- and Gi(1/2)-proteins indicated that Gi(3)peptide specifically blocked the mastoparan-stimulated secretory activity, which indicates an involvement of a trimeric Gi(3)-protein in mastoparan-stimulated secretory activity. Flash photolysis of caged Ca(2+)-elicited biphasic capacitance increases consisting of a fast and a slower component. Injection of anti-Gi(3) antibodies selectively inhibited the slow but not the fast component of secretory activity in rat melanotrophs. We propose that the plasma membrane-bound Gi(3)-protein may be involved in regulated secretion by specifically controlling the slower kinetic component of exocytosis.

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