Salinity-dependent copy number increase of a marine cyanobacterial endogenous plasmid

Listeria monocytogenes possessed glucose oxidase and NADH oxidase activities in whole cells and lysed protoplasts respectively. The NADH oxidase activity sedimented with the membrane fraction and was inhibited by the respiratory inhibitors rotenone, 2-heptyl-4-hydroxy-quinoline-N-oxide and cyanide, suggesting the presence of a membrane associated respiratory chain.     

Analysis of differential accumulation of winged bean Kunitz chymotrypsin inhibitor mRNA species by a sequence-specific termination method

Winged bean Kunitz chymotrypsin inhibitor (WCI) is encoded by a multigene family and accumulation of its mRNA is restricted in mid-maturation stage seeds and tuberous roots. In this paper, we analyzed the accumulation of mRNA derived from each WCI gene using a novel method: sequence-specific termination analysis. The results demonstrated that the accumulation of each WCI mRNA was differentially regulated in winged bean plants.     

Inhibition of the alpha- and beta-carbonic anhydrases from the gastric pathogen Helycobacter pylori with anions

The gastric pathogen Helicobacter pylori encodes two carbonic anhydrases (CAs, EC 4.2.1.1), an α- and a β-class one, hpαCA and hpβCA, crucial for its survival in the acidic environment from the stomach. Sulfonamides, strong inhibitors of these enzymes, block the growth of the pathogen, in vitro and in vivo. Here we report the inhibition of the two H. pylori CAs with inorganic and complex anions and other molecules interacting with zinc proteins. hpαCA was inhibited in the low micromolar range by diethyldithiocarbamate, sulfamide, sulfamic acid, phenylboronic acid, and in the submillimolar one by cyanide, cyanate, hydrogen sulfide, divanadate, tellurate, perruthenate, selenocyanide, trithiocarbonate, iminodisulfonate. hpβCA generally showed a stronger inhibition with most of these anions, with several low micromolar and many submillimolar inhibitors detected. These inhibitors may be used as leads for developing anti-H. pylori agents with a diverse mechanism of action compared to clinically used antibiotics.     

A biophysical and computational study unraveling the molecular interaction mechanism of a new Janus kinase inhibitor Tofacitinib with bovine serum albumin

The interaction of a recently certified kinase inhibitor Tofacitinib (TFB) with bovine serum albumin (BSA) has been studied, by spectroscopic and molecular docking studies. Spectrofluorimetric measurements at 3 different temperatures (288, 298, and 310 K) showed that TFB quench the intrinsic fluorescence of BSA upon forming a nonfluorescent complex. The intrinsic fluorescence data showed that TFB binds to BSA with binding constant (K _b) of approximately 10⁴M⁻¹, affirming a significant affinity of TFB with BSA. The decrease in Stern‐Volmer quenching constant with increasing temperature exhibited the static mechanism of quenching. Negative value of ΔG (−6.94 ± 0.32 kcal·mol⁻¹), ΔH (−7.87 ± 0.52 kcal·mol⁻¹), and ΔS (−3.14 ± 0.42 cal·mol⁻¹·K⁻¹) at all 3 temperatures declared the reaction between BSA and TFB to be spontaneous and exothermic. Far‐UV circular dichroism spectroscopy results demonstrated an increase in helical content of BSA in the presence of TFB. Moreover, dynamic light scattering measurements showed that TFB resulted into a decrease in the hydrodynamic radii (from 3.6 ± 0.053 to 2.9 ± 0.02 nm) of BSA. Molecular docking studies confirmed that TFB binds near site II on BSA, hydrogen bonding, and hydrophobic interaction were involved in the BSA‐TFB complex formation. The present study characterizing the BSA‐TFB interaction could be significant towards gaining an insight into the drug pharmacokinetics and pharmacodynamics and also in the direction of rational drug designing with better competence, against emerging immune‐mediated diseases, ie, alopecia and rheumatoid arthritis.     

Novel benzimidazole derivatives as phosphodiesterase 10A (PDE10A) inhibitors with improved metabolic stability

In this study, we report the identification of potent benzimidazoles as PDE10A inhibitors. We first identified imidazopyridine 1 as a high-throughput screening hit compound from an in-house library. Next, optimization of the imidazopyridine moiety to improve inhibitory activity gave imidazopyridinone 10b. Following further structure–activity relationship development by reducing lipophilicity and introducing substituents, we acquired 35, which exhibited both improved metabolic stability and reduced CYP3A4 time-dependent inhibition.     

A New Tiazofurin Pronucleotide: Synthesis and Biological Evaluation of CycloSaligenyl-Tiazofurin Monophosphate

Abstract

Synthesis and biological activities of cyclosaligenyl-tiazofurin monophosphate (CycloSal-TRMP), a new tiazofurin pronucleotide, are reported. CycloSal-TRMP proved to be active in vitro against human myelogenous leukemia K562 cell line and as A₁ adenosine receptor agonist.     

Increase of cyclin B by overexpression of cystatin α

Degradation of cyclin B was effectively suppressed when cells were treated with ALLN (N-acetylleucylleucylnorleucinal) which inhibits proteasome, calpain and cysteine proteinase cathepsins. In order to examine which protease degrades cyclin B, the effect of a cathepsin inhibitor, cystatin α, was investigated. The cystatin α gene was inserted into an inducible expression vector, pMSG, and transfected into NIH3T3 mouse fibroblasts. The expression of cystatin α was induced effectively in the transfected cells after treatment with dexamethasone. Overexpression of cystatin α resulted in an increase of the amount of cyclin B, suggesting that cysteine proteinase cathepsins might be involved in the degradation of cyclin B.     

Engineering Halomonas TD01 for the low-cost production of polyhydroxyalkanoates

The halophile Halomonas TD01 and its derivatives have been successfully developed as a low-cost platform for the unsterile and continuous production of chemicals. Therefore, to increase the genetic engineering stability of this platform, the DNA restriction/methylation system of Halomonas TD01 was partially inhibited. In addition, a stable and conjugative plasmid pSEVA341 with a high-copy number was constructed to contain a LacI^q-P_trc system for the inducible expression of multiple pathway genes. The Halomonas TD01 platform, was further engineered with its 2-methylcitrate synthase and three PHA depolymerases deleted within the chromosome, resulting in the production of the Halomonas TD08 strain. The overexpression of the threonine synthesis pathway and threonine dehydrogenase made the recombinant Halomonas TD08 able to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) or PHBV consisting of 4–6 mol% 3-hydroxyvalerate or 3HV, from various carbohydrates as the sole carbon source. The overexpression of the cell division inhibitor MinCD during the cell growth stationary phase in Halomonas TD08 elongated its shape to become at least 1.4-fold longer than its original size, resulting in enhanced PHB accumulation from 69 wt% to 82 wt% in the elongated cells, further promoting gravity-induced cell precipitations that simplify the downstream processing of the biomass. The resulted Halomonas strains contributed to further reducing the PHA production cost.     

Effects of Tripeptides on the Amidolytic Activities of Urokinase, Thrombin, Plasmin and Trypsin

Eight peptides of the general formula X-d-Ser-AA-Arg-Y where X = H, Ac; AA = Ala, Gly and Y = OH, NH₂ were obtained and tested for their effect on the amidolytic activities of urokinase, thrombin, plasmin, and trypsin.