Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epithelial and connective tissue compartments of rat oral mucosa were dissociated after incubation with elastase +/- soybean trypsin inhibitor (SBTI). Elastase + SBTI induced greater ultrastructural damage within the dissociated compartments than elastase alone. The basal lamina remained with the epithelial layer after elastase separation and was destroyed after exposure to elastase + SBTI. Isolated epithelial mitochondria were more severely damaged ultrastructurally after elastase + SBTI separation of the compartment than those prepared after exposure to elastase alone. Isolated fibroblast mitochondria were damage to the same extent after dissociation of the compartment with either medium. Oxidative metabolism and mitochondrial recoveries declined significantly after exposure to either dissociating medium. Cytochrome oxidase activity was significantly greater than succinic cytochrome c reductase in the control and experimental groups. Oxidative metabolism was found to be significantly greater in the connective tissue compartment than the epithelial compartment after dissociation of immature rat oral mucosa. Our data suggests that caution be utilized in assessing cellular viability and oxidative metabolism in tissue compartments immediately after their dissociation by proteolytic enzymes.
 ...
PMID:Elastase +/- soybean trypsin inhibitor dissociation of rat oral mucosa: ultrastructural and oxidative metabolic destructive changes in isolated, epithelial and dermal mitochondria after dissociation. 690 88

NADPH diaphorase activity was found in membrane of DMSO-induced differentiated human promyelocytic leukemia HL-60 cells. This membrane-bound diaphorase activity increased dramatically during differentiation of HL-60 cells. A dye reductase was extracted from membrane of DMSO-induced differentiated HL-60 cells with n-octyl glucoside and sodium cholate in the presence of several protease inhibitors such as PMSF, DIFP, TLCK, antipain, chymostatin, leupeptin, pepstatin A and trypsin inhibitor. The NADPH diaphorase was highly purified by two-stage sequential column chromatographies. The purified enzyme, showing both SOD-insensitive cytochrome c and NBT reductase activities, migrated with an apparent molecular mass of 77 kDa on SDS-PAGE. When the purification of this diaphorase was carried out in the presence of only three protease inhibitors, PMSF, DIFP and TLCK, a partially proteolyzed form of the diaphorase with a molecular mass of 68 kDa was prepared. The proteolyzed diaphorase exhibited only an NADPH-dependent cytochrome c reductase. The NADPH diaphorase gave a positive cross-reaction to polyclonal antibodies raised against microsomal NADPH-cytochrome P450 reductase from rabbit liver.
 ...
PMID:Purification of an NADPH-dependent diaphorase from membrane of DMSO-induced differentiated human promyelocytic leukemia HL-60 cells. 769 24

Spin-trapping with 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) was used to demonstrate that 3-nitrotyrosine (nitrotyrosine) promotes the formation of substantial amounts of reactive oxygen species (O2.- and *OH), when incubated with NAD(H)-cytochrome c reductase and a corresponding electron donor. Spin adduct formation is strongly inhibited by the presence of superoxide dismutase (SOD); spin adduct formation requires aerobic conditions. Nitration of leucine enkephalin, a tyrosine-containing pentapeptide, results in a similar generation of O2*- and *OH species. Both nitrotyrosine and nitrated leucine enkephalin stimulate acetylated ferricytochrome c reduction in the presence of NAD(H)-cytochrome c reductase with typical Michaelis-Menten kinetics and Km's of 104 +/- 14 and 0.78 +/- 0.11 microM, respectively. No stimulation of acetylated ferricytochrome c reduction is observed in the presence of SOD. Catalase and the metal chelators DTPA and deferoxamine mesylate do not influence observed stimulation of acetylated ferricytochrome c reduction by nitrotyrosine. Nitration of two tyrosines (of four) within the sequence of the 6.5-kDa globular protein bovine pancreas trypsin inhibitor (BPTI) fails to stimulate O2*- generation implying steric restrictions for BPTI-reductase interactions. However, nitrated BPTI subjected to trypsin digestion stimulated reduction of acetylated ferricytochrome c. These results suggest that, as with other nitroaromatic compounds, nitrotyrosine may be enzymatically reduced to the corresponding nitro anion radical (ArNO2*-) which is then oxidized by molecular oxygen to yield O2*- and regenerate ArNO2. Thus, once formed in vivo, nitrotyrosine may act to promote oxidative stress by means of repetitive redox cycling.
 ...
PMID:Enzymatic reduction of 3-nitrotyrosine generates superoxide. 958 80