Mammalian methionine adenosyltransferase II (MAT II) is the only hetero-oligomer in this family of enzymes that synthesize S-adenosylmethionine using methionine and ATP as substrates. Binding of regulatory β subunits and catalytic α2 dimers is known to increase the affinity for methionine, although scarce additional information about this interaction is available. This work reports the use of r...

Escherichia coli class Ia ribonucleotide reductase (RNR) converts ribonucleotides to deoxynucleotides. A diferric-tyrosyl radical (Y122•) in one subunit (β2) generates a transient thiyl radical in another subunit (α2) via long-range radical transport (RT) through aromatic amino acid residues (Y122 ⇆ [W48] ⇆ Y356 in β2 to Y731 ⇆ Y730 ⇆ C439 in α2). Equilibration of Y356•, Y731•, and Y730• was re...

In this study, the effect of α-adrenoceptor agents on imipramine-induced antinociception was investigated using formalin test. Intraperitoneal (i.p.) administration of imipramine at different doses (10-80 mg/kg) induced antinociception in both phases of formalin test. In addition, intracerebroventricular (i.c.v.) injection of imipramine (1, 5, and 10 µg/rat) did not elicit any effect, although ...

Clonidine is a classically categorized α2-adrenoceptor (α2-AR) agonist that produces vascular contractions by stimulating arterial smooth muscle α2-ARs. However, clonidine inhibits α1-AR-mediated arterial contractions. Recently, it was suggested that repeated stimulation with clonidine induces desensitization of α2-ARs, thus inhibiting noradrenaline-induced smooth muscle contractions. In the pr...

Proof Fix a satisfying assignment a. Define the distance of r to a, denoted dist(r, a), as the number of coordinates where ri 6= ai (this is called Hamming distance). Let r = r, r, r, · · · be the assignments generated by the algorithm, and let di = dist(r , a). Note that as we only change one bit of the assignment, di+1 = di + ∆i where ∆i ∈ {−1, 1}. We claim that Pr[∆i = −1] ≥ 1/2. Once this i...

BACKGROUND Variations in the GABRA2 gene, encoding α2 subunits of GABAA receptors, have been associated with risk for addiction to several drugs, but the mechanisms by which variations in non-coding regions of GABRA2 increase risk for addictions are not understood. Mice with deletion of GABRA2 show deficits in the ability of psychostimulants to facilitate responding for conditioned reinforcers,...

On the basis of the results outlined in our previous report, bacterial sialyltransferases (ST) from marine sources were further characterized using glycosphingolipids (GSL), especially ganglio-series GSLs, based on the enzymatic characteristics and kinetic parameters obtained by Line weaver-Burk plots. Among them, GA1 and GA2 were found to be good substrates for these unique STs. Thus, new gang...

We describe the production of a highly-active mutant VEGF variant, α2-PI1-8-VEGF121, which contains a substrate sequence for factor XIIIa at the aminoterminus designed for incorporation into a fibrin gel. The α2-PI1-8-VEGF121 gene was synthesized, cloned into a pET-32a(+) vector and expressed in Escherichia coli Origami B (DE3) host cells. To increase the protein folding and the solubility, the...

Progesterone (P) binding to the intracellular progesterone receptors (PRs) plays a key role in epilepsy via modulation of GABA-A receptor plasticity in the brain. This is thought to occur via conversion of P to neurosteroids such as allopregnanolone, an allosteric modulator of GABA-A receptors. In the female brain, the composition of GABA-A receptors is not static and undergoes dynamic spatial ...

COP (coat protein) I-coated vesicles mediate intra-Golgi transport and retrograde transport from the Golgi to the endoplasmic reticulum. These vesicles form through the action of the small GTPase ADP-ribosylation factor 1 (ARF1) and the COPI heptameric protein complex (coatomer), which consists of seven subunits (α-, β-, β'-, γ-, δ-, ε- and ζ-COP). In contrast to mammals and yeast, several isof...