PURPOSE To delineate the role of the glutathione S-transferase (GST) isozyme hGST 5.8 in protection mechanisms against oxidative stress, the effect of low-level transient exposure of H2O2 to retinal pigmented epithelial (RPE) cells on hGST 5.8 and other enzymes involved in defense against oxidative stress was examined. METHODS Cultured human RPE cells were exposed to 50 microM H2O2 for 20 min...

We have shown previously that bovine heart fructose-6-phosphate 2-kinase/fructose-2,6-bisphosphatase (EC 2.7.1.105/3.1.3.46) is phosphorylated by cAMP-dependent protein kinase and protein kinase C; phosphorylation results in activation of kinase. This activation of heart enzyme is in contrast to results with the liver isozyme, in which phosphorylation by cAMP-dependent protein kinase inhibits t...

Membrane transport systems participate in fundamental activities such as cell cycle control, proliferation, survival, volume regulation, pH maintenance and regulation of extracellular matrix synthesis. Multiple isoforms of Na(+), K(+)-ATPase are expressed in primary chondrocytes. Some of these isoforms have previously been reported to be expressed exclusively in electrically excitable cells (i....

Differences in the catalytic activity of the placental and gonadal isozymes of porcine aromatase cytochrome P450 (P450arom) were examined in cell lines exhibiting stable expression of recombinant enzyme. Cell lines were selected that expressed high, but similar, immunodetectable levels of each isozyme based on Western analysis. Aromatase activity varied with growth in culture, decreasing at con...

Isozyme phenotypes were determined for 101 strains of Gibberella fujikuroi and 2 strains of Gibberella nygamai that represent seven biological species (mating populations) isolated from a variety of plant hosts in dispersed geographic locations. Fourteen enzymes were resolved in one or more of three buffer systems. Two of the enzymes, arylesterase and acid phosphatase, were polymorphic within t...

The molecular basis of the classical human phosphoglucomutase 1 (PGM1) isozyme polymorphism has been established. In 1964, when this genetic polymorphism was first described, two common allelozymes PGM1 and PGM1 2 were identified by starch gel electrophoresis. The PGM1 2 isozyme showed a greater anodal electrophoretic mobility than PGM1 1. Subsequently, it was found that each of these allelozym...

Acceleration of glycolysis is, in general, a characteristic of neoplasia. Previous studies have shown that this increase in glycolysis is achieved by quantitative increases in the activities of the key regulatory enzymes, hexokinase, phosphofructokinase (PFK) and/or pyruvate kinase, which are often accompanied by isozymic alterations that facilitate glycolysis. In this study, we investigated th...

Pumpkin (Cucurbita moschata) samples showing yellow vein mosaic disease in Varanasi region were identified with begomovirus infection using PCR amplification. A sequencing analysis of the full genome revealed that it is a strain of Tomato leaf curl Palampur virus (GenBank ID. FJ931537). Phytochemical composition and antioxidative enzyme levels were compared in infected and healthy plants. The s...

Diphenhydramine is widely used as an over-the-counter antihistamine. However, the specific human cytochrome P450 (P450) isozymes that mediate the metabolism of diphenhydramine in the range of clinically relevant concentrations (0.14-0.77 microM) remain unclear. Therefore, P450 isozymes involved in N-demethylation, a main metabolic pathway of diphenhydramine, were identified by a liquid chromato...

Normal feline and human arylsulfatase B isozymes were purified to homogeniety from liver. The specific activities of the feline and human enzymes toward p-nitrocatechol sulfate were 1,100,000 and 800,000 units/mg of protein, and toward UDP-N-acetylgalactosamine-4-sulfate were 5,500 and 4,000 units/mg of protein, respectively. Although both enzymes had the same pH optimum (5.7), the feline enzym...