The enzyme creatine kinase (CK) [EC 2.7.3.2] is a dimeric molecule consisting of two separate subunits Band M, giving rise to three isoenzymes CK-BB, CK-MB and CK-MM. Most of the CK found in the plasma of normal individuals is the MM isoenzyme derived from skeletal muscle, while the CK-MB fraction originates predominately from cardiac muscle. Normally there is little, if any, CK-BB isoenzyme pr...

I measured total creatine kinase (CK; EC 2.7.3.2) activity and isoenzyme pattern in normal and neoplastic tissues. CK activity was detected in all of them examined. In various tumors it was greater than, less than, or the same as that in normal tissue, no clear correlation being seen between total activity and growth rate or degree of differentiation. In several cases, there was a greater propo...

Aqueous extracts of seeds of Duranta plumieri were found to be rich in polyphenol oxidase activity. The anion-exchange chromatography of the crude extract on Streamline DEAE resolved the activity into three fractions. The major fraction (77% of the total activity) was further purified by treating it with concanavalin A-agarose in the batch mode. The enzyme preparation eluting with alpha-methylm...

The isoenzymes of glucose 6-phosphate dehydrogenase (G6PD) and láclate dehydrogenase (LDH) were studied in R3230AC mammary adenocarcinomas and normal mammary glands of Fischer rats at various times during and after the administration of estradiol-17/3. Total activities of G6PD and LDH were elevated in response to treatment with estrogen; however, only certain isoenzyme species were increased b...

To the Editor: The last step in electrophoretic procedures for creatine kinase (CK; EC 2.7.3.2) isoenzyme separation on cellulose acetate is to incubate the plate with a reagent that will develop either fluorescence or color for each isoenzyme. In our laboratory we routinely use fluorescence to detect the isoenzymes. The reagent used must be highly sensitive, so that low proportions of the isoe...

Shikimate kinase II was purified to near homogeneity from an Escherichia coli strain which overproduced the enzyme. The apparent Km of this isoenzyme for shikimate was 200 microM, and for ATP it was 160 microM. The Km for shikimate is approximately 100-fold lower than the Km of shikimate kinase I, suggesting that shikimate kinase II is the isoenzyme normally functioning in aromatic biosynthesis...

Because of its sensitivity to disturbances of excretory liver function, gamma-glutamyltransferase (GGT; EC 2.3.2.2) assay has become one of the most important diagnostic tests for hepatobiliary disorders. However, its value in the differential diagnosis of liver diseases is limited. It is present in kidney, liver, pancreas, and intestine in electrophoretically distinct but not necessarily organ...

To separate the MM and MB creatine kinase (EC 2.7.3.2) isoenzymes in small plasma samples, we developed a simple, rapid ion-exchange batch-adsorption procedure with "DEAE Glycophase" glass beads (Corning). All separative steps are performed in a single test tube and can be completed within a few minutes. Results of measurements of isoenzymes in plasma samples from patients with acute myocardial...

A new isoenzyme of alkaline phosphatase (EC 3.1.3.1) has been reported to occur in sera from patients with lymphoproliferative diseases. This enzyme is character ized by an inability to hydrolyze cysteamine S-phosphate. We find that the 5,5 -dithobis(2-nitrobenzoic acid)-coupled assay method for cysteamine S-phosphate hydrolysis is not suitable for serum, and we were unable to confirm the exist...

The human leukemic cell lines HL60 and K562, were induced to differentiate terminally by chemical agents. The isoenzyme patterns of lactate dehydrogenase (LD) in the cells before and after differentiation were determined electrophoretically on agarose gels. In general, treatment of the leukemic cells with inducers of differentiation resulted in a quantitative shift of the isoenzyme pattern towa...