The Influence of Chaotropic Reagents on Neuronal Nitric Oxide Synthase and Its Flavoprotein Module. Urea and Guanidine Hydrochloride Stimulate NADPH–Cytochrome c Reductase Activity of Both Proteins

Nitric Oxide ◽  
1997 ◽  
Vol 1 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Ramani Narayanasami ◽  
Jonathan S. Nishimura ◽  
Kirk McMillan ◽  
Linda J. Roman ◽  
Thomas M. Shea ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cytochrome C ◽  
Reductase Activity ◽  
Guanidine Hydrochloride ◽  
Neuronal Nitric Oxide Synthase ◽  
Cytochrome C Reductase ◽  
Nadph Cytochrome ◽  
Oxide Synthase ◽  
Nadph Cytochrome C Reductase

scholarly journals Identification and characterization of a calmodulin-dependent nitric oxide synthase from GH3 pituitary cells

1992 ◽  
Vol 285 (1) ◽  
pp. 201-206 ◽  
Author(s):  
D J Wolff ◽  
G A Datto
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cytochrome C ◽  
Specific Activity ◽  
Reductase Activity ◽  
Deae Cellulose ◽  
Bovine Brain ◽  
Pituitary Cells ◽  
Cytochrome C Reductase ◽  
Oxide Synthase

A nitric oxide synthase activity stimulated more than 30-fold by the concurrent presence of Ca2+ and calmodulin (CaM), and inhibited by trifluoperazine (50 microM), has been identified in extracts of GH3 pituitary cells. The CaM-dependent nitric oxide synthase of the crude extract was stimulated more than 9-fold by (6R)-5,6,7,8-tetrahydro-L-biopterin with half-maximal stimulation occurring at a concentration of 300 nM. Fractionation of the extract on DEAE-cellulose enhanced nitric oxide synthase specific activity up to 300-fold and provided a preparation which on Western blot analysis possessed a 152 kDa protein which cross-reacted with antibodies to homogeneous bovine brain nitric oxide synthase. The DEAE-cellulose-purified enzyme exhibited apparent Km values of 4.3 microM, 0.4 microM, 0.3 microM and 4 nM for L-arginine, NADPH, Ca2+ and CaM respectively. The CaM-dependent nitric oxide synthase of GH3 extract bound to 2′,5′-ADP-agarose and was eluted by NADPH with a 500-fold increased specific activity. Citrulline formation by the ADP-agarose-purified enzyme was inhibited by NG-nitro-L-arginine, NG-methyl-L-arginine and Nitro Blue Tetrazolium with apparent Ki values of 0.2, 1.8 and 7 microM respectively. The ADP-agarose-purified enzyme displayed cytochrome c reductase activity which was stimulated more than 18-fold by the concurrent presence of Ca2+ and CaM and inhibited by trifluoperazine. NG-Nitro-L-arginine and NG-methyl-L-arginine did not inhibit the cytochrome c reductase activity.

scholarly journals Ca2+/calmodulin-dependent cytochrome c reductase activity of brain nitric oxide synthase.

1992 ◽  
Vol 267 (16) ◽  
pp. 11374-11378
Author(s):  
P Klatt ◽  
B Heinzel ◽  
M John ◽  
M Kastner ◽  
E Böhme ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cytochrome C ◽  
Reductase Activity ◽  
Cytochrome C Reductase ◽  
Oxide Synthase ◽  
Brain Nitric Oxide

Temperature Influence on Basal Activity and Induction of Mixed Function Oxygenase Activity in Fundulus heteroclitus

1979 ◽  
Vol 36 (11) ◽  
pp. 1400-1405 ◽  
Author(s):  
John J. Stegeman
Keyword(s):  
Cytochrome C ◽  
Fundulus Heteroclitus ◽  
Reductase Activity ◽  
Control Fish ◽  
Cytochrome C Reductase ◽  
Nadph Cytochrome ◽  
Pyrene Hydroxylase ◽  
Mixed Function Oxygenase ◽  
Cytochrome P 450 ◽  
Nadph Cytochrome C Reductase

Treatment of Fundulus heteroclitus acclimated to 6.5 °C with benzo(a)pyrene did not elicit any change in the levels of hepatic microsomal NADH- or NADPH-cytochrome c reductase activity, nor in the levels of cytochrome P-450 or its catalytic activities. However, the same treatment offish at 16 5 °C resulted in a marked induction of benzo(a)pyrene hydroxylase and NADPH-cytochrome c reductase. Cytochrome P-450 content was also higher in the warm, treated fish and the Soret maximum of reduced, CO-treated microsomes was shifted to the violet. Levels of aminopyrine demethylase and NADH-cytochrome c reductase activities did not show a significant treatment effect. At neither temperature could treated and control fish be distinguished on the basis of in vitro inhibition of benzo(a)pyrene hydroxylase activity by 7,8-benzoflavone. Levels of NADPH-cytochrome c reductase and benzo(a)pyrene hydroxylase activities were greater in control Fundulus acclimated to 6.5 °C than to 16.5 °C, when normalized to microsomal protein, but not when based on body weight. The results indicate that habitat temperature alone may not affect the capacity for initial hydrocarbon metabolism in fish, but that it can strongly influence the induction of cytochrome P-450. Key words: temperature, cytochrome P-450, hydrocarbon metabolism, mixed-function oxygenase, Fundulus heteroclitus

A chimeric iron-sulfur flavoprotein endowed with NADPH-cytochrome c reductase activity

1996 ◽  
Vol 24 (1) ◽  
pp. 22S-22S ◽  
Author(s):  
Giuliana Zanetti ◽  
Luciano Piubelli ◽  
Roberta Zucca Tanci ◽  
Alessandro Aliverti
Keyword(s):  
Cytochrome C ◽  
Reductase Activity ◽  
Cytochrome C Reductase ◽  
Nadph Cytochrome ◽  
Iron Sulfur ◽  
Nadph Cytochrome C Reductase
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