Synthesis, in vitro, and in vivo evaluation of novel N-phenylindazolyl diarylureas as potential anti-cancer agents.

Novel N-phenylindazole based diarylureas have been designed, synthesized and evaluated as potential anticancer agents. In vitro cell viability studies of these derivatives illustrate good potency with IC values in the range of 0.4-50 μM in several cancer cell lines including murine metastatic breast cancer 4T1, murine glioblastoma GL261, human triple negative breast cancer MDA-MB-231, human pancreatic cancer MIAPaCa-2, and human colorectal cancer cell line WiDr.

Synthesis and Evaluation of Baylis-Hillman Reaction Derived Imidazole and Triazole Cinnamates as Antifungal Agents.

Allylic acetates derived from Baylis-Hillman reaction undergo efficient nucleophilic isomerization with imidazoles and triazoles to provide imidazolylmethyl and triazolylmethyl cinnamates stereoselectively. Antifungal evaluation of these derivatives against exhibits good minimum inhibitory concentration values. These compounds exhibit low toxicity in proliferating MCF-7 breast cancer cell line.

Decarbamoylation of acetylcholinesterases is markedly slowed as carbamoyl groups increase in size.

Carbamates are esters of substituted carbamic acids that react with acetylcholinesterase (AChE) by initially transferring the carbamoyl group to a serine residue in the enzyme active site accompanied by loss of the carbamate leaving group followed by hydrolysis of the carbamoyl enzyme. This hydrolysis, or decarbamoylation, is relatively slow, and half-lives of carbamoylated AChEs range from 4 min to more than 30 days. Therefore, carbamates are effective AChE inhibitors that have been developed as insecticides and as therapeutic agents.

Stereoselective synthesis of pyroglutamate natural product analogs from α- aminoacids and their anti-cancer evaluation.

Alkylation of α-amino acid derived iminoesters with Baylis-Hillman (BH) reaction template based allyl bromides/allyl acetates followed by acidic hydrolysis furnished α-methylene-β-substituted-pyroglutamates and α-alkylidene pyroglutamates respectively. Application of these methodologies has been demonstrated in the synthesis of fused [3.2.

Application of a Bioinformatics-Based Approach to Identify Novel Putative in vivo BACE1 Substrates.

BACE1, a membrane-bound aspartyl protease that is implicated in Alzheimer's disease, is the first protease to cut the amyloid precursor protein resulting in the generation of amyloid-β and its aggregation to form senile plaques, a hallmark feature of the disease. Few other native BACE1 substrates have been identified despite its relatively loose substrate specificity. We report a bioinformatics approach identifying several putative BACE1 substrates.

Molecular basis of inhibition of substrate hydrolysis by a ligand bound to the peripheral site of acetylcholinesterase.

Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to the catalytic efficiency of substrate hydrolysis by transiently binding substrates on their way to the acylation site, where a short-lived acyl enzyme intermediate is produced. Ligands that bind to the A-site invariably inhibit the hydrolysis of all AChE substrates, but ligands that bind to the P-site inhibit the hydrolysis of some substrates but not others.

Analysis of the reaction of carbachol with acetylcholinesterase using thioflavin T as a coupled fluorescence reporter.

Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to catalytic efficiency by transiently binding substrates on their way to the acylation site, where a short-lived acylated enzyme intermediate is produced. Carbamates are very poor substrates that, like other AChE substrates, form an initial enzyme-substrate complex with free AChE (E) and proceed to an acylated enzyme intermediate (EC), which is then hydrolyzed.

Monitoring the reaction of carbachol with acetylcholinesterase by thioflavin T fluorescence and acetylthiocholine hydrolysis.

Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to catalytic efficiency by transiently binding substrates on their way to the acylation site, where a short-lived acyl enzyme intermediate is produced. Carbamates are very poor substrates that, like other AChE substrates, form an initial enzyme-substrate complex and proceed to an acylated enzyme intermediate which is then hydrolyzed.

Clinical heterogeneity of the LRRK2 G2019S mutation.

Background: Several pathogenic mutations have been reported in the leucine-rich repeat kinase 2 gene (LRRK2) that cause parkinsonism. The "common" LRRK2 G2019S kinase domain substitution has been reported to account for approximately 5% of familial and 1% of sporadic Parkinson disease.

Objective: To observe the clinical heterogeneity presented by LRRK2 kinase mutation carriers.

Evidence for a synergistic salt-protein interaction -- complex patterns of activation vs. inhibition of nitrogenase by salt.

The molybdenum nitrogenase enzyme system, comprised of the MoFe protein and the Fe protein, catalyzes the reduction of atmospheric N(2) to NH(3). Interactions between these two proteins and between Fe protein and nucleotides (MgADP and MgATP) are crucial to catalysis. It is well established that salts are inhibitors of nitrogenase catalysis that target these interactions.

Lrrk2 and Lewy body disease.

Objective: The Lrrk2 kinase domain G2019S substitution is the most common genetic basis of familial and sporadic parkinsonism. Patients harboring the G2019S substitution usually present with clinical Parkinson's disease.

Methods: Herein, we report that the most common neuropathology of G2019S-associated Parkinson's disease is Lewy body disease.

Interactions between the peripheral site and the acylation site in acetylcholinesterase.

Acetylcholinesterase (AChE) hydrolyzes its physiological substrate acetylcholine at one of the highest known catalytic rates. Two sites of ligand interaction have been identified: an acylation site or A-site at the base of the active site gorge, and a peripheral site or P-site at its mouth. Despite a wealth of information about the AChE structure and the role of specific residues in catalysis, an understanding of the catalytic mechanism and the role of the P-site has lagged far behind.

Inhibitors tethered near the acetylcholinesterase active site serve as molecular rulers of the peripheral and acylation sites.

The acetylcholinesterase (AChE) active site consists of a narrow gorge with two separate ligand binding sites: an acylation site (or A-site) at the bottom of the gorge where substrate hydrolysis occurs and a peripheral site (or P-site) at the gorge mouth. AChE is inactivated by organophosphates as they pass through the P-site and phosphorylate the catalytic serine in the A-site. One strategy to protect against organophosphate inactivation is to design cyclic ligands that will bind specifically to the P-site and block the passage of organophosphates but not acetylcholine.

Unmasking tandem site interaction in human acetylcholinesterase. Substrate activation with a cationic acetanilide substrate.

Acetylcholinesterase (AChE) contains a narrow and deep active site gorge with two sites of ligand binding, an acylation site (or A-site) at the base of the gorge, and a peripheral site (or P-site) near the gorge entrance. The P-site contributes to catalytic efficiency by transiently binding substrates on their way to the acylation site, where a short-lived acyl enzyme intermediate is produced. A conformational interaction between the A- and P-sites has recently been found to modulate ligand affinities.