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We have previously reported that methylation of catecholamines by catechol-O-methyltransferase (COMT) was attenuated in spontaneously hypertensive rats (SHR) with acute hypotension as compared with that of Wistar-Kyoto (WKY) rats. Here we examined the soluble (S-) and membrane-bound (MB-) COMT activities and COMT protein in the liver, kidney, and erythrocytes in both strains. Both the activities a
Phospholamban ablation in the mouse is associated with significant increases in cardiac contractility. To determine whether this hyperdynamic function persists through the aging process, a longitudinal examination of age-matched phospholamban-deficient and wild-type mice was employed. Kaplan-Meier survival curves indicated no significant differences between phospholamban-deficient and wild-type mi
Levosimendan is an inodilatory drug that mediates its cardiac effect by the calcium sensitization of contractile proteins. The target protein of levosimendan is cardiac troponin C (cTnC). In the current work, we have studied the interaction of levosimendan with Ca2+-saturated cTnC by heteronuclear NMR and small angle x-ray scattering. A specific interaction between levosimendan and the Ca2+-loaded
Levosimendan, an inodilatory drag discovered using troponin C as a target protein, has a cardiac effect deriving from the calcium sensitization of contractile proteins. The aim of this study was to give further evidence that levosimendan binds to cardiac troponin C and that the binding involves amino acid residues on helix ε of the N-terminal domain of this calcium-binding protein. Nine organic mo
Phenotype mining is a novel approach for elucidating the genetic basis of complex phenotypic variation. It involves a search of rich phenotype databases for measures correlated with genetic variation, as identified in genome-wide genotyping or sequencing studies. An initial implementation of phenotype mining in a prospective unselected population cohort, the Northern Finland 1966 Birth Cohort (NFB
Catechol-O-methyl transferase (COMT) expression is higher in leiomyomas compared with paired normal myometrium. The expression of COMT in leiomyoma cells is hormonally regulated-estrogen down-regulates, whereas P and dexamethasone up-regulate, COMT expression.
Importance: This follow-up study of extremely preterm (EPT) children (<27 weeks' gestational age [GA] at birth) revealed major eye and visual problems in 37.9% (147 of 388) of all EPT infants and in 55.4% (67 of 121) of the most immature subgroups at 6.5 years of age. These major eye and visual problems were strongly associated with treatment-requiring retinopathy of prematurity (ROP).Objectives:
Conformations of the regulatory domain of cardiac troponin C (cNTnC) were studied by means of residual dipolar couplings measured from samples dissolved in dilute liquid crystals. Changes in the main chain HN residual dipolar couplings revealed a conformational change in cNTnC due to the complexation with the second binding region (amino acids 148-163) of cardiac troponin I (cTnI). Formation of th
Phospholamban is an inhibitor of the sarcoplasmic reticulum Ca2+ transport apparent affinity for Ca2+ in cardiac muscle. This inhibitory effect of phospholamban can be relieved through its phosphorylation or ablation. To better characterize the regulatory mechanism of phospholamban, we examined the initial rates of Ca2+-uptake and Ca2+-ATPase activity under identical conditions, using sarcoplasmic
Thee three-dimensional structure of calcium-loaded regulatory, i.e. N- terminal, domain (1-91) of human cardiac troponin C (cNTnC) was determined by NMR in water/trifluoroethanol (91:9 v/v) solution. The single-calcium-loaded cardiac regulatory domain is in a 'closed' conformation with comparatively little exposed hydrophobic surface. Difference distance matrices computed from the families of Ca2+
The intracellular localization of soluble and membrane-bound isoforms of rat and human catechol O-methyltransferase (COMT) was studied by expressing the recombinant COMT proteins either separately or together in mammalian cell lines (HeLa and COS-7 cells) and in rat primary neurons. The distribution of soluble and membrane-bound COMT enzyme was visualized by immunocytochemistry. For comparison, th
The catechol-O-methyltransferase (COMT) gene occurs as two polymorphic alleles, which code for a high activity thermostable and low activity thermolabile form of the enzyme. We devised a fast solid-phase minisequencing assay for genotyping the COMT gene at nucleotide position 544 encoding amino acid residue 158. The method was applied to correlate the genotype of the COMT gene with the biological
Phospholamban ablation is associated with significant increases in the sarcoplasmic reticulum Ca2+-ATPase activity and the basal cardiac contractile parameters. To determine whether the observed phenotype is due to loss of phospholamban alone or to accompanying compensatory mechanisms, hearts from phospholamban-deficient and age-matched wild-type mice were characterized in parallel. There were no
The protein purification strategies used for obtaining homogeneous rat and human soluble catechol-O-methyltransferase (S-COMT) polypeptides are reviewed. Expression and purification of recombinant rat and human S-COMT in Escherichia coli and for human S-COMT in baculovirus-infected insect cells made it possible to elucidate the S-COMT polypeptides in more detail. The application of these purificat
Localization of catechol-O-methyltransferase (COMT) in rat cerebral cortex, neostriatum and cerebellar cortex was studied with pre-embedding immunoelectron microscopy using a specific antiserum raised against rat recombinant COMT protein. In all areas, immunoreactivity was found both in astrocytes and in neuronal processes. Reaction product was seen in the cytoplasm and in association with tubular
BACKGROUND: High-fat diet has been known to have adverse effects on metabolic markers, as well as the gut microbiota. However, the effect of heat processing of high-fat diet, which leads to formations of advanced glycation end products (AGEs) has not been clearly distinguished from the effect of unheated fat. This study compared the effect of high-fat diet with heat-treated high-fat diet on adipos
Bacillus stearothermophilus α-amylase has a signal peptide typical for proteins exported by Gram-positive bacteria. There is only one signal peptidase processing site when the protein is exported from the original host, but when it is exported by Escherichia coli, two alternative sites are utilized. Site-directed mutagenesis was used to study the processing in E. coli. Processing sites for 13 B. s
Previous biochemical and histochemical studies have suggested that catechol-O-methyltransferase (COMT) is a predominantly glial enzyme in the brain. The aim of this work was to study its localization and molecular forms in primary cultures, where cell types can be easily distinguished with specific markers. COMT immunoreactivity was studied in primary astrocytic cultures from newborn rat cerebral
