Exactly why N-acetyl-beta-D-glucosaminidase (NAG) excretion is increased in patients with nephrotic syndrome with glomerular lesions is poorly understood. Glomeruli contain less NAG than do proximal tubules. In this study, we have tried to measure the NAG isoenzymes automatically by use of the recently developed fast protein liquid chromatography (FPLC) system, followed by column chromatography...

1. Differentiation and maturation of rabbit bone-marrow erythroid cells was accompanied by a 15-fold decrease in lactate dehydrogenase activity from approx. 0.1pmol of NADH utilized/min per cell in basophilic cells to 0.007 pmol of NADH/min per cell in reticulocytes. 2. In early cells, cell division takes place with a corresponding decrease in cell volume, but the concentration of lactate dehyd...

BACKGROUND Paraoxonase 1 (PON1), an esterase that hydrolyzes toxic organophosphates and has antioxidative and antiatherogenic properties, contains a common polymorphism at position 192: glutamine (Q) or arginine (R). The Q and R isoenzymes exhibit different physical and protective properties. We describe 2 methods for quantifying their serum activity levels. METHODS We measured serum hydrolyt...

The chloroplast and cytoplasmic isoenzymes of phosphoglycerate kinase (PGK) (EC. 2.7.2.3) from Hordeum vulgare leaves have been separated and purified for the first time to apparent homogeneity. The method for purifying the isoenzymes is described here and consists of DEAE Sephacel chromatography followed by affinity chromatography on ATP Sepharose. This consistently provided a 500- to 900-fold...

The alkaline phosphatase activity expressed by JAR choriocarcinoma cells was compared to the placental isoenzyme of human alkaline phosphatase by several criteria. JAR cell alkaline phosphatase was similar to the placental isoenzyme with respect to heat and urea stability and sensitivity to most inhibitors, but it differed significantly from placental alkaline phosphatase in its sensitivity to ...

Human serous-type ovarian tumors contain an acidic isoenzyme of amylase. Previous attempts at purification of tumor amylases have yielded preparations contaminated with other proteins. The purification scheme presented here incorporates an affinity-chromatography procedure, with use of cycloheptaamylose linked to epoxy-activated Sepharose, that is specific for alpha-amylase (EC 3.2.1.1). Purifi...

Two cases of congestive cardiac failure had unusually high activities of serum lactate dehydrogenase and lactate dehydrogenase isoenzyme-5. Values for isoenzyme-5 exceeding 87% of the total serum activity, and increases of 228- to 380-fold of the upper reference limit, are very uncommon.

SUMMARY Glucose 6-phosphate isoenzyme patterns and chromosomes were studied in 25 primary liver tumors of the rat in order to determine whether the isoenzyme pattern and chromosomes change dependently upon neoplastic transformation, and whether certain changes in the isoenzyme patterns correlate with definite chromosomal changes. Tumors were induced in livers of male rats fed 3'-methyl-4-dimeth...

The primary structure of mitochondrial aspartate aminotransferase from chicken is reported. The enzyme is a dimer of identical subunits. Each subunit contains 401 amino acid residues; the calculated subunit molecular weight of the apoform is 44,866. The degree of sequence identity with the homologous cytosolic isoenzyme from chicken is 46%. A comparison of the primary structures of the mitochon...