Nine new microsatellite loci for the roundnose grenadier (Coryphaenoides rupestris) with four showing cross-amplification in the shortbeard grenadier (C. brevibarbis)

We isolated nine new microsatellites for the deep-sea fish Coryphaenoides rupestris. These loci are highly polymorphic, with allele number ranging from 14 to 42 and heterozygosity ranging from 0.647 to 0.965. Four of these loci also amplified in C. brevibarbis.     

Potent pyrrolidine- and piperidine-based BACE-1 inhibitors

Based on lead compound 1 identified from the patent literature, we developed novel patentable BACE-1 inhibitors by introducing a cyclic amine scaffold. Extensive SAR studies on both pyrrolidines and piperidines ultimately led to inhibitor 2f, one of the most potent inhibitors synthesized to date.     

In vitro properties of a recombinant flavonol synthase from Arabidopsis thaliana

cDNA corresponding to a flavonol synthase gene from Arabidopsis thaliana was cloned and expressed in Escherichia coli. The recombinant protein was purified to near-homogeneity and the catalytic properties of the enzyme were studied in vitro. Together with kaempferol and apigenin the recombinant protein synthesised the (2R,3S)-cis- and (2S,3S)-trans-isomers of dihydrokaempferol from the (2S)- and (2R)-isomers of naringenin, respectively. Flavanones and dihydroflavanols differing in degree of A- or B-ring hydroxylation were also accepted as substrates.     

Production and characterization of a thermostable alpha-amylase from Nocardiopsis sp. endophyte of yam bean

Thermostable amylolytic enzymes have been currently investigated to improve industrial processes of starch degradation. Studies on production of alpha-amylase by Nocardiopsis sp., an endophytic actinomycete isolated from yam bean (Pachyrhizus erosus L. Urban), showed that higher enzyme levels were obtained at the end of the logarithmic growth phase after incubation for 72 h at pH 8.6. Maximum activity of alpha-amylase was obtained at pH 5.0 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C, and 50% of residual activity at 90 degrees C for 10 min. Extracellular enzyme from Nocardiopsis sp. was purified by fractional precipitation with ammonium sulphate. After 60% saturation produced 1130 U mg-1 protein and yield was 28% with purification 2.7-fold. The enzyme produced by Nocardiopsis sp. has potential for industrial applications.     

Effect of chronic paroxetine treatment on 5-HT1B and 5-HT1D autoreceptors in rat dorsal raphe nucleus

This study reports the effect of chronic paroxetine (10 mg/kg p.o., 21 days) on 5-HT1B and 5-HT1D autoreceptors controlling stimulated 5-HT efflux in slices of rat dorsal raphe nucleus. Electrically evoked 5-HT (10 pulses, 200 Hz, 0.1 ms, 10 mA) was measured using fast cyclic voltammetry. 5-HT efflux was inhibited by CP 93129 (10 nM-10 microM) and by sumatriptan (1 nM-1 microM) agonists at 5-HT1B and 5-HT1D receptors, respectively. Chronic paroxetine did not, initially, appear to alter the sensitivity of the 5-HT1B autoreceptors to CP 93129. However, when constructed in the presence of WAY 100635 (10 nM) the selective and silent 5-HT1A antagonist, there was a significant (P < 0.001) rightward shift of the CP 93129 concentration-response curve in the paroxetine-treated rats but not in the controls, implying a desensitisation of the 5-HT1B autoreceptor by paroxetine. Chronic paroxetine did not affect the sumatriptan concentration-response curve, even with WAY 100635 present, implying that there was no (de)sensitisation of the 5-HT1D autoreceptor. These data suggest that chronic paroxetine treatment may desensitise 5-HT1B autoreceptors in the dorsal raphe nucleus but that this effect is unmasked only when the dominant 5-HT1A autoreceptor control is antagonised.     

Production and characterization of a thermostable glucoamylase from Streptosporangium sp. endophyte of maize leaves

Thermostable amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Streptosporangium sp. an endophytic actinomycete isolated from leaves of maize (Zea mays L.) showed glucoamylase production, using starch-Czapek medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 8.0. Maximum glucoamylase activity (158 U mg(-1) protein) was obtained at pH 4.5 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C for 30 min with total inhibition at 100 degrees C. Extracellular enzyme from Streptosporangium sp. was purified by fractionated precipitation with ammonium sulphate. After 60% saturation produced 421 U mg(-1) protein, and yield was 74% with purification 2.7 fold. The enzyme produced by Streptosporangium sp. has potential for industrial applications.