Liver microsomes from rabbits treated chronically with ethanol were solubilized and fractionated to yield a new isozyme of cytochrome P-450 in a homogeneous state. This cytochrome, designated as isozyme 3a on the basis of its relative electrophoretic mobility, is distinct from the known terminal amino acid sequences. In addition, peptide mapping by high performance liquid chromatography followi...

Changes in the properties of cyclic AMP-dependent protein kinase were studied in the kidney of hypothyroid rats. The activity of the crude extract was greater in hypothyroid rats than in normal ones. The ratio of type I isozyme to type II isozyme in hypothyroid rats was about twice that in the normal rats with enzymes from both the cortex and medulla. A higher affinity for the substrates was sh...

Salmonid fish, as a result of total genome duplication, have two genes, Ldh H and Ldh H', coding for polypeptides H and H', respectively, both of which have been shown in their tetrameric forms to be immunologically related to the classical H-4 lactate dehydrogenase isozyme of higher vertebrates (Bailey, G. S., and Wilson, A. C. (1968) J. Biol. Chem. 243,5843). The H-4 and H'-4 isozymes have no...

Overproduction of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in yeast resulted in striking morphological effects on the structure of intracellular membranes. Specifically, stacks of paired membranes closely associated with the nuclear envelope were observed in strains that over-produced the HMG1 isozyme, one of two isozymes for HMG-CoA reductase in yeast. These nuclear...

A previously undetected Bacillus subtilis aspartokinase isozyme, which we have called aspartokinase III, has been characterized. The new isozyme was most readily detected in extracts of cells grown with lysine, which repressed aspartokinase II and induced aspartokinase III, or in extracts of strain VS11, a mutant lacking aspartokinase II. Antibodies against aspartokinase II did not cross-react ...

The goal of this study was to define Na,K-ATPase α and β subunit isoform expression and isozyme composition in colorectal cancer cells and liver metastases. The α1, α3, and β1 isoforms were the most highly expressed in tumor cells and metastases; in the plasma membrane of non-neoplastic cells and mainly in a cytoplasmic location in tumor cells. α1β1 and α3β1 isozymes found in tumor and metastat...

It is well established that the gills of teleost fish contain substantial levels of cytoplasmic carbonic anhydrase (CA), but it is unclear which CA isozyme(s) might be responsible for this activity. The objective of the current study was to determine if branchial CA activity in rainbow trout was the result of a general cytoplasmic CA isozyme, with kinetic properties, tissue distribution and phy...

By employing a pharmacological approach, we have shown that phospholipase C (PLC) activity is involved in the regulation of gene expression of transcription factors such as c-Fos and c-Jun in cardiomyocytes in response to norepinephrine (NE). However, there is no information available regarding the identity of specific PLC isozymes involved in the regulation of c-Fos and c-Jun or on the involve...

We have previously identified three types of protein kinase C (a Ca2+-activated phospholipid-dependent kinase) isozymes, designated types I, II, and III, from rat brain (Huang, K.-P., Nakabayashi, H., and Huang, F. L. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 8535-8539). These enzymes are different in their elution profile from hydroxylapatite column, sites of autophosphorylation, and immunore...

Two isozymes of the Na,K-ATPase are made in the brain and retina. Antisera have been produced that contain antibodies specific for each of the catalytic subunits of the two isozymes, alpha and alpha(+) (Sweadner & Gilkeson, 1985a). To determine which classes of cells express which form of the Na,K-ATPase, and whether cells can express both forms, the antisera were used to stain sections of the ...