The extent of equilibrium perturbation of the DNA helix associated with enzymatic methylation of dA residues has been determined by the agarose gel electrophoresis band-shift method. Utilization of EcoRI methylase under conditions of reduced specificity together with Escherichia coli dam methylase permitted modification of up to 300 dA residues/plasmid pBR322 dimer. A conformational change asso...

S-adenosylmethionine synthesis is a key process for cell function, and needs to be regulated at multiple levels. In recent years, advances in the knowledge of methionine adenosyltransferases have been significant. The discovery of nuclear localization of these enzymes suggests their transport to provide the methyl donor, S-adenosylmethionine, for DNA and histone methyltransferases in epigenetic...

Target engagement is a critical factor for therapeutic efficacy. Assessment of compound binding to native target proteins in live cells is therefore highly desirable in all stages of drug discovery. We report here the first compound library screen based on biophysical measurements of intracellular target binding, exemplified by human thymidylate synthase (TS). The screen selected accurately for...

POMT7, which is an O-methyltransferase from poplar, transfers a methyl group to several flavonoids that contain a 7-hydroxyl group. POMT7 has been shown to have a higher affinity toward quercetin, and the reaction product rhamnetin has been shown to inhibit the formation of beta-amyloid. Thus, rhamnetin holds great promise for use in therapeutic applications; however, methods for mass productio...

A microarray-based resonance light scattering assay, with the combination of methylation-sensitive endonuclease and gold nanoparticle (GNP) probes, has been proposed to sensitively distinguish the DNA methylation level as low as 0.01% (10 pM methylated DNA in 100 nM total DNA) and detect human DNA methyltransferase 1 (Dnmt1) down to 0.1 U mL(-1).

Gokhan Ozan Cetin1, Vildan Caner1, Nilay Sen Turk2, Volkan Okur1, Ozge Can3, Saadettin Eskicorapci4, Levent Tuncay4, Levent Elmas3, Gulseren Bagci1 1. Pamukkale University, School of Medicine, Department of Medical Genetics, Denizli, Turkey 2. Pamukkale University, School of Medicine, Department of Pathology, Denizli, Turkey 3. Pamukkale University, School of Medicine, Department of Medical Bio...

A functional variant of the catechol-O-methyltransferase (COMT) gene [val158met (rs4680)] is frequently implicated in decision-making and higher cognitive functions. It may achieve its effects by modulating dopamine-related decision-making and reward-guided behaviour. Here we demonstrate that individuals with the met/met polymorphism have greater responsiveness to reward than carriers of the va...

OBJECTIVE The authors examined the distribution of catechol O-methyltransferase (COMT) genotypes in patients with panic disorder as well as the relationship between a COMT polymorphism and the clinical characteristics of these patients. METHOD Fifty-one patients with panic disorder and 45 healthy comparison subjects were tested for a genetic polymorphism of COMT. Clinical variables were asses...

L-Asparaginyl and L-aspartyl residues in proteins are subject to spontaneous degradation reactions that generate isomerized and racemized aspartyl derivatives. Proteins containing L-isoaspartyl and D-aspartyl residues can have altered structures and diminished biological activity. These residues are recognized by a highly conserved cytosolic enzyme, the protein L-isoaspartate(D-aspartate) O-met...

O-Methylguanine (OmeG) is one of the most toxic, mutagenic, and carcinogenic lesions caused by the interaction of DNA with several catabolism products as well as with environmental methylating agents. Carcinogenic impact of OmeG can be conditioned not only by its mutagenic properties but also by alteration in enzymatic methylation of the C5 carbon atom of cytosine residue in CpG sequences. In t...