Search results for "Isozyme"
showing 10 items of 102 documents
Role of cyclic nucleotide phosphodiesterase isoenzymes in contractile responses of denuded rat aorta related to various Ca 2+ sources
2001
We have examined the cyclic nucleotide phosphodiesterase isoforms (PDE) involved in the contractile response of rat aorta to different agonists and different experimental procedures for use in functional studies. The inhibitory effect of AAL 05 on the different PDEs isolated from bovine aortic smooth muscle was examined. Compound AAL 05 appeared to be a selective PDE3 inhibitor. We analyzed the ability of the non-selective inhibitor IBMX (3-isobutyl-1-methylxanthine) and the isoenzyme selective inhibitors nimodipine (type 1), AAL 05 (6-(N-methyl-N-cyclohexyl butyl carboxamide) quinolin-2-one) and SKF 94120 (5-(4-acetamidophenyl) pyrazin-2(1H)-one; type3), rolipram (type4) and zaprinast (typ…
Nitric oxide synthase isozymes. Characterization, purification, molecular cloning, and functions.
1994
Three isozymes of nitric oxide (NO) synthase (EC 1.14.13.39) have been identified and the cDNAs for these enzymes isolated. In humans, isozymes I (in neuronal and epithelial cells), II (in cytokine-induced cells), and III (in endothelial cells) are encoded for by three different genes located on chromosomes 12, 17, and 7, respectively. The deduced amino acid sequences of the human isozymes show less than 59% identity. Across species, amino acid sequences for each isoform are well conserved (> 90% for isoforms I and III, > 80% for isoform II). All isoforms use L-arginine and molecular oxygen as substrates and require the cofactors NADPH, 6(R)-5,6,7,8-tetrahydrobiopterin, flavin adenine…
Nitric oxide synthase isozymes antibodies
1995
Three isozymes of nitric oxide synthase (NOS) have been identified, cDNAs isolated and sequenced, and antibodies produced against each isozyme. Isozyme I (found primarily in central and peripheral neuronal cells), II (in cytokine-induced cells), and III (in endothelial cells) show less than 58% identity in the deduced amino acid sequences from humans. Many investigators have produced isozyme-specific antibodies and used these antibodies to locate these proteins in various cells and tissues. NOS-I is constitutively expressed, and the enzymatic activity is regulated by Ca2+ and calmodulin. The anti-NOS-I antibodies have allowed investigators to characterize non-adrenergic non-cholinergic neur…
Changes in the genetic diversity of barley of Nordic and Baltic origin, studied by isozyme electrophoresis
2003
AbstractIn this study an evaluation was made of changes in the genetic variation of barley (Hordeum vulgare L.) of Nordic and Baltic origin, from the end of the 19th century until today. A comparison of Nordic and Baltic material with exotic material that has not been subjected to intense selection was also made. A total of 293 accessions, including 160 Nordic and 80 Baltic landraces, cultivars and breeding lines, and another 53 landraces of exotic origin (Central Asia), were surveyed using isozyme starch gel electrophoresis. For the four isozymes studied, 28 alleles at 11 loci were observed. The average total genetic diversity value (HT) for individual loci ranged between 0 and 0.519. In t…
Assessing the genetic diversity ofCentaurea parlatorisgroup (sect.Dissectae, Compositae) in Sicily using isozymes
2011
Abstract The Centaurea parlatoris group belongs to sect. Dissectae and is one of the most taxonomically critical groups in Sicily. The taxa included in it inhabit dry slopes, pastures and rocky places. Some of them are narrow endemics to Sicily, and others to Italy. The great morphological variability at the intrapopulation level has not permitted the creation of an adequate taxonomic scheme. The recent proposal of two new species from Sicily confirms the insufficient knowledge of the taxonomic diversity. This study involves eight Sicilian populations of the C. parlatoris group. Seven loci from nine enzyme systems [isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), 6-phosphoglucona…
Isolation and biodiversity inCytisus villosusPourret (Fabaceae, Genisteae): enzyme polymorphism in disjunct populations
1997
ABSTRACT The genetic diversity of isolated populations of Cytisus villosus has been studied by means of enzyme polymorphism analysis. Two types of isolated populations were studied: “terrestrial islands” in Sicily, and “true islands” in the Aeolian archipelago. In the populations of “true islands” the number of alleles and the heterozygosity are lower than in “terrestrial islands”. Isolation amongst Sicilian populations seems to be more recent than isolation of the Aeolian populations, and may be attributed to climatic changes which occurred during the Holocene and/or to human activities. The disjunction of the Aeolian populations seems much more recent than the origin of the isles themselv…
Genome-Based Examination of Chlorophyll and Carotenoid Biosynthesis in Chlamydomonas reinhardtii
2005
Abstract The unicellular green alga Chlamydomonas reinhardtii is a particularly important model organism for the study of photosynthesis since this alga can grow heterotrophically, and mutants in photosynthesis are therefore conditional rather than lethal. The recently developed tools for genomic analyses of this organism have allowed us to identify most of the genes required for chlorophyll and carotenoid biosynthesis and to examine their phylogenetic relationships with homologous genes from vascular plants, other algae, and cyanobacteria. Comparative genome analyses revealed some intriguing features associated with pigment biosynthesis in C. reinhardtii; in some cases, there are additiona…
CYP2D6 increases toxicity of the designer drug 4-methylthioamphetamine (4-MTA)
2006
4-Methylthioamphetamine (4-MTA) belongs to a group of new amphetamine derivatives that is usually sold as "ecstasy" or "flatliners" on the illicit drug market. Large interindividual differences in 4-MTA mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 4-MTA. For this purpose, we used the colony formation assay with Chinese hamster lung fibroblast V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low activity alleles CYP2D6*2, CYP2D6*9, as well as human CYP3A4. The obtained results showed that the expression of wild type CYP2D6*1 clearly enhanced the susceptibility to the cyt…
Seed isozyme variation in Petrocoptis A. Braun (Caryophyllaceae).
2001
Abstract The electrophoretic patterns of seven isozyme systems (ADH, AMY, AAT, GDH, LAP, MDH, and SOD) obtained from dormant seeds from 44 accessions belonging to 12 Petrocoptis taxa were compared in order to clarify taxonomic relationships within the genus. Overall, electrophoretic zymograms showed the presence of up 28 electromorphs, of which 26 were polymorphic among accessions. Mantel tests revealed a moderate level of correlation between the geographic distance matrix and several dissimilarity matrices based on the isozyme data ( r =0.3052–0.3376). The electrophoretic profiles of seed isozymes did not match closely the analytical taxonomic framework drawn from morphology. Many electrom…
Acid Dnase Activities In Peripheral, Mononuclear Blood Cells: A Possible Parameter To Detect Proliferating Cell Populations
1992
After electrophoresis in DNA -containing polyacrylamide gels, two acid DNase activities can be detected in peripheral, mononuclear cells of the human blood. One of these acid DNase activities correlates with cell proliferation; its isoelectrical point is at pI 7.4. By means of this DNase activity, a quantity of less than 1% leukemic cells can be detected. The increased acid DNase activity can indicate the proliferation of malignant cell populations and possibly the proliferation of cell populations during immunological reactions