SUMMARY Pyruvate kinase (PK) (EC 2.7.1.40) isozymes were assayed in normal rat liver and a series of transplantable rat hepatomas ranging widely in growth rate and degree of differentiation, with the use of gradient elution by chloride ion from columns of DEAE-cellulose. In agreement with other studies, three noninterconvertible forms were found in rat tissues: isozyme I, the major form in adul...

The activities of cardiac protein kinase C (PKC) were examined in hemodynamically assessed rats subsequent to myocardial infarction (MI). Both Ca(2+)-dependent and Ca(2+)-independent PKC activities increased significantly in left ventricular (LV) and right ventricular (RV) homogenates at 1, 2, 4, and 8 wk after MI was induced. PKC activities were also increased in both LV and RV cytosolic and p...

In a recent study on Gulf War veterans who developed delayed neurotoxicity symptoms, we found their levels of serum paraoxonase (PON1) isozyme type Q to be significantly lower than in the control, unaffected veteran group. These results were obtained in 25 ill veterans and 20 well control subjects, of which 10 were deployed and 10 were nondeployed battalion members who remained in the United St...

Glycolate oxidase (GLO) is a key enzyme in photorespiratory metabolism. Four putative GLO genes were identified in the rice genome, but how each gene member contributes to GLO activities, particularly to its isozyme profile, is not well understood. In this study, we analyzed how each gene plays a role in isozyme formation and enzymatic activities in both yeast cells and rice tissues. Five GLO i...

Esterase activity between the resistant Crawford and susceptible CSMA strains of German cockroach, Blattella germanica (L.), was compared with the substrates alpha- and beta-naphthyl acetate across sex and nymphal age classes. Esterase isozyme analysis with native polyacrylamide gel electrophoresis also was conducted to identify quantitative and qualitative differences between strains, sexes, a...

This research investigated the role of oxidative enzymes in the defense response of buffalograss,Buchloë dactyloides (Nuttall) Engelmann, toBlissus occiduusBarber. Changes in catalase and peroxidase activity were observed in both resistant and susceptible buffalograsses in response to chinch bug feeding. Susceptible plants were shown to have a lower level of catalase activity compared with thei...

This research investigated the role of oxidative enzymes in the defense response of buffalograss, Buchloë dactyloides (Nuttall) Engelmann, to Blissus occiduus Barber. Changes in catalase and peroxidase activity were observed in both resistant and susceptible buffalograsses in response to chinch bug feeding. Susceptible plants were shown to have a lower level of catalase activity compared with t...

OBJECTIVE To investigate how acetamiprid, a new insecticide, affects the activity of superoxide dismutase (SOD), catalase (CAT), and ATPase and the SOD isozyme patterns in two G bacteria, E. coli K12 and Pse.FH2, and one G+ bacterum, B. subtilis. METHODS The SOD, CAT, and ATPase specific activities of cell lysates were determined spectrophotometrically at 550 nm, 240 nm, and 660 nm, respectiv...

BACKGROUND AND PURPOSE Stroke is a leading cause of disability and death in the United States, yet limited therapeutic options exist. The need for novel neuroprotective agents has spurred efforts to understand the intracellular signaling pathways that mediate cellular response to stroke. Protein kinase C (PKC) plays a central role in mediating ischemic and reperfusion damage in multiple tissues...

Chromatographic analysis of organelle-associated citrate synthase activity revealed distinct mitochondrial and glyoxysomal forms of the enzyme. The chromatographic elution patterns on hydroxylapatite, carboxymethylcellulose and DEAE-cellulose of citrate synthase from the endosperm of 4.5-day-old castor bean seedlings revealed significant differences for mitochondrial and glyoxysomal activities ...