Knowledge-based prediction of DNA hydration using hydrated dinucleotides as building blocks.

Water plays an important role in stabilizing the structure of DNA and mediating its interactions. Here, the hydration of DNA was analyzed in terms of dinucleotide fragments from an ensemble of 2727 nonredundant DNA chains containing 41 853 dinucleotides and 316 265 associated first-shell water molecules. The dinucleotides were classified into categories based on their 16 sequences and the previously determined structural classes known as nucleotide conformers (NtCs).

Synthetic testosterone derivatives modulate rat P2X2 and P2X4 receptor channel gating.

P2X receptors (P2XRs) are ATP-gated cationic channels that are allosterically modulated by numerous compounds, including steroids and neurosteroids. These compounds may both inhibit and potentiate the activity of P2XRs, but sex steroids such as 17β-estradiol or progesterone are reported to be inactive. Here, we tested a hypothesis that testosterone, another sex hormone, modulates activity of P2XRs.

3,5,7-Substituted Pyrazolo[4,3- d]pyrimidine Inhibitors of Cyclin-Dependent Kinases and Their Evaluation in Lymphoma Models.

Cyclin-dependent kinases are therapeutic targets frequently deregulated in various cancers. By convenient alkylation of the 5-sulfanyl group, we synthesized 3-isopropyl-7-[4-(2-pyridyl)benzyl]amino-1(2) H-pyrazolo[4,3- d]pyrimidines with various substitutions at position 5 with potent antiproliferative activity in non-Hodgkin lymphoma cell lines. The most potent derivative 4.

Strong Inhibitory Effect, Low Cytotoxicity and High Plasma Stability of Steroidal Inhibitors of -Methyl-D-Aspartate Receptors With C-3 Amide Structural Motif.

Herein, we report the synthesis, structure-activity relationship study, and biological evaluation of neurosteroid inhibitors of -methyl-D-aspartate receptors (NMDARs) receptors that employ an amide structural motif, relative to pregnanolone glutamate (PAG) - a compound with neuroprotective properties. All compounds were found to be more potent NMDAR inhibitors (IC values varying from 1.4 to 21.

Positive Modulators of the N-Methyl-d-aspartate Receptor: Structure-Activity Relationship Study of Steroidal 3-Hemiesters.

Here, we report the synthesis of pregn-5-ene and androst-5-ene dicarboxylic acid esters and explore the structure-activity relationship (SAR) for their modulation of N-methyl-d-aspartate receptors (NMDARs). All compounds were positive modulators of recombinant GluN1/GluN2B receptors (EC varying from 1.8 to 151.

Structural Basis of the Interaction of Cyclin-Dependent Kinase 2 with Roscovitine and Its Analogues Having Bioisosteric Central Heterocycles.

The structural basis for the interaction of roscovitine and analogues containing 13 different bioisosteric central heterocycles with the enzyme cyclin-dependent kinase 2 (CDK2) is elucidated. Although all the central scaffolds are very similar to the purine core of roscovitine, the experimentally determined IC values of the inhibitors span three orders of magnitude. By using an extensive computational chemistry approach, the affinities of the inhibitors to CDK2 are determined as calculated binding scores of complexes of the inhibitors with the protein.

Distributions of therapeutically promising neurosteroids in cellular membranes.

Interactions of two neurosteroids, inhibiting membrane-bound N-Methyl-d-aspartate receptors, with phospholipid membranes are studied. Namely, endogenous pregnanolone sulfate is compared with pregnanolone glutamate, the latter being a novel synthetic steroidal inhibitor of these receptors with potential pharmaceutical use. Molecular-level details of steroid-phospholipid membranes interactions are scrutinized employing molecular dynamics simulations supported by quantum chemical calculations to assess steroid lipophilicity.

Physicochemical and biological properties of novel amide-based steroidal inhibitors of NMDA receptors.

Herein, we report a new class of amide-based inhibitors (1-4) of N-methyl-d-aspartate receptors (NMDARs) that were prepared as analogues of pregnanolone sulfate (PAS) and pregnanolone glutamate (PAG) - the steroidal neuroprotective NMDAR inhibitors. A series of experiments were conducted to evaluate their physicochemical and biological properties: (i) the inhibitory effect of compounds 3 and 4 on NMDARs was significantly improved (IC=1.0 and 1.

Neurosteroid-like Inhibitors of N-Methyl-d-aspartate Receptor: Substituted 2-Sulfates and 2-Hemisuccinates of Perhydrophenanthrene.

N-Methyl-d-aspartate receptors (NMDARs) display a critical role in various diseases of the central nervous system. The activity of NMDARs can be modulated by neurosteroids. Herein, we report a structure-activity relationship study for perhydrophenanthrene analogues possessing a framework that mimics the steroidal ring system.

Preferential Inhibition of Tonically over Phasically Activated NMDA Receptors by Pregnane Derivatives.

Unlabelled: Postsynaptic N-methyl-d-aspartate receptors (NMDARs) phasically activated by presynaptically released glutamate are critical for synaptic transmission and plasticity. However, under pathological conditions, excessive activation of NMDARs by tonically increased ambient glutamate contributes to excitotoxicity associated with various acute and chronic neurological disorders. Here, using heterologously expressed GluN1/GluN2A and GluN1/GluN2B receptors and rat autaptic hippocampal microisland cultures, we show that pregnanolone sulfate inhibits NMDAR currents induced by a prolonged glutamate application with a higher potency than the NMDAR component of EPSCs.

A New Class of Potent N-Methyl-D-Aspartate Receptor Inhibitors: Sulfated Neuroactive Steroids with Lipophilic D-Ring Modifications.

N-Methyl-D-aspartate receptors (NMDARs) are glutamate-gated ion channels that play a crucial role in excitatory synaptic transmission. However, the overactivation of NMDARs can lead to excitotoxic cell damage/death, and as such, they play a role in numerous neuropathological conditions. The activity of NMDARs is known to be influenced by a wide variety of allosteric modulators, including neurosteroids, which in turn makes them promising therapeutic targets.