Search results for "Isoenzyme"

Fast Regulation of Cytochrome P450 Activities by Phosphorylation and Consequences for Drug Metabolism and Toxicity

2002

In contrast to the well-known regulation of cytochrome P450 (CYP) activity by enzyme induction, which represents a process with slow onset and slow offset, more recent studies revealed phosphorylation as a fast (within observation instantaneous) and isoenzyme-selective regulation. The phosphorylated enzyme (investigated isozyme: CYP2B1) was fully inactive. The phosphorylation is mediated by PKA and hence under control of hormones and drugs that alter cellular cAMP levels. The consequences for the metabolic control of toxic species derived from drugs and environmental carcinogens are discussed. This information will help to improve therapy with drugs metabolized by CYPs which are phosphoryla…

LACTATE DEHYDROGENASE ISOENZYMES IN THE NERVOUS TISSUE?V..

1965

LACTATE-DEHYDROGENASE ISOENZYMES IN NERVOUS TISSUE. II. A COMPARATIVE ANALYSIS IN VERTEBRATES.

1963

LACTATE DEHYDROGENASE ISOENZYMES IN THE NERVOUS TISSUE. IV. AN ONTOGENETIC STUDY ON THE RAT BRAIN.

1964

Therapeutic administration of 3,4,5-trimethoxy-4'-fluorochalcone, a selective inhibitor of iNOS expression, attenuates the development of adjuvant-in…

2003

We have previously investigated the effects of a series of dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, on nitric oxide production in LPS-stimulated murine RAW 264.7. The present study was designed to determine if 3,4,5-trimethoxy-4'-fluorochalcone (CH 17) could modulate the production of NO and/or prostaglandins in vivo. On the mouse macrophage cell line RAW 264.7 CH 17 inhibited dose-dependently NO production, with an IC(50) value in the nanomolar range, and reduced PGE(2) levels by a 58% at 10 microM. This compound had no direct inhibitory effect on iNOS and COX-2 activities. NO reduction was the consequence of inhibition of the expression of iNOS…

Differential subcellular localization of endogenous and transfected soluble epoxide hydrolase in mammalian cells: evidence for isozyme variants

1999

AbstractEndogenous, constitutive soluble epoxide hydrolase in mice 3T3 cells was localized via immunofluorescence microscopy exclusively in peroxisomes, whereas transiently expressed mouse soluble epoxide hydrolase (from clofibrate-treated liver) accumulated only in the cytosol of 3T3 and HeLa cells. When the C-terminal Ile of mouse soluble epoxide hydrolase was mutated to generate a prototypic putative type 1 PTS (-SKI to -SKL), the enzyme targeted to peroxisomes. The possibility that soluble epoxide hydrolase-SKI was sorted slowly to peroxiosmes from the cytosol was examined by stably expressing rat soluble epoxide hydrolase-SKI appended to the green fluorescent protein. Green fluorescent…

Enzymes involved in the dynamic equilibrium of core histone acetylation ofPhysarum polycephalum

1992

DEAE-Scpharose chromatography of extracts from plasmodia of the myxomyccte PI~.~suru~~t ,~/.~crpl~~ho~~ revealed the presence of multiple histone acetyltransferases and histonc deacctylascs. A cyloplasmic histonc acctyltransferase B, specific for histonc H4, and two nuclear acetyltransferases Al and A2 were identilied; Al acetylates all core hislones with a preference for l-13 and H2A. whereas A2 is specific for H3 and also slightly for H2B. Two hislone deacetylases. HDI and HD2, could be discriminated. They differ with respect to subslralc speciliciiy and pH dependence. For the first time the substrate specificity of histonc deacetylascs was determined using HPLC-purilicd individual core h…

A Biochemical Genetic Study of Isoenzyme Polymorphism within and between Two Populations of Atherina Boyeri Risso

1996

Allozymic variation of 20 loci was investigated in two samples of Atherina boyeri collected in the Mediterranean Sea from the coast of Trappeto and Marsala Lagoon (Sicily, Italy). Five loci were polymorphic (PGM*, EST-1,2*, SOD-2*, PGI-2*) and appeared to be in Hardy-Weinberg equilibrium. A significant Fst mean value (0.02) (G = 23.77, P < 0.05, df = 5) showed that the samples can be considered as two distinct local populations and supports previous morphometric discrimination.

Nitric Oxide/Cyclic Guanosine Monophosphate Signaling via Guanylyl Cyclase Isoform 1 Mediates Early Changes in Synaptic Transmission and Brain Edema …

2021

Traumatic brain injury (TBI) often induces structural damage, disruption of the blood-brain barrier (BBB), neurodegeneration, and dysfunctions of surviving neuronal networks. Nitric oxide (NO) signaling has been suggested to affect brain functions after TBI. The NO exhibits most of its biological effects by activation of the primary targets-guanylyl cyclases (NO-GCs), which exists in two isoforms (NO-GC1 and NO-GC2), and the subsequently produced cyclic guanosine monophosphate (cGMP). However, the specific function of the NO-NO-GCs-cGMP pathway in the context of brain injury is not fully understood. To investigate the specific role of the isoform NO-GC1 early after brain injuries, we perfor…

Alternatively spliced transcripts of the thymus-specific protease PRSS16 are differentially expressed in human thymus.

2004

The putative serine protease PRSS16 is abundantly expressed in the thymic cortex and the gene is encoded within the HLA I complex. Although its function is not yet defined, the very restricted expression points to a role in T-cell development in the thymus. In this study, we show that the PRSS16 mRNA is alternatively spliced to generate at least five transcripts. Apart from the full-length sequence, we found two other isoforms with all putative active site residues of the serine protease, suggesting that those variants may also be functional. Semi-quantitative analysis of the splice variants in different tissue samples revealed a strong correlation between the specific formation of alternat…