ABSTRACT
Cathepsin B from Helicoverpa armigera (HCB) belongs to the group of cysteine proteinases. HCB is proved being involved in the degradation of yolk proteins during embryonic development,which is an acidic preferring enzyme and is resistant to SDS. The expression of the proenzyme may offer a model for investigating the activation of the enzyme. The HCB gene was constructed into pPIC9K and expressed in Pichia pastoris KM71 strain . After induction by methanol, HCB was expressed and secreted into the medium. The molecular weight of the recombinant procathepsin B was determined as about 38 kDa. The expressed product was confirmed to be HCB by immunoblotting assay using specific rabbit anti-HCB polyclonal antibody. The activity of the product was assayed by in situ hydrolysis (gelatin-SDS-PAGE). These results showed that HCB with proteolytic activity was expressed in P. pastoris KM71. This proenzyme can be used for further research on the activation of the proenzyme or industrial production.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the improvement of taurine (Tau) in learning and memory ability of rats exposed to lead.</p><p><b>METHODS</b>Forty Wistar rats were randomly divided into control group: treated with distilled water; lead group: treated with lead acetate (40 mg.kg(-1).d(-1)); lead-taurine group 1, 2, 3: lead acetate (40 mg.kg(-1).d(-1)) + different concentrations of taurine (100, 400, 800 mg.kg(-1).d(-1)). The ability of learning and memory of rats were measured weekly by spatial water maze test from the 5th to 8th week. At the end of the experiment, the rats were killed, the samples of blood and brain were taken for test.</p><p><b>RESULTS</b>(1) The time of seeking anchorage of lead-Tau 800 mg group in the 6th, 7th, 8th week and that of lead-Tau 400 mg group in the 6th week were significantly lower than that of lead group (P<0.05). (2) Blood lead contents in lead-Tau 100 mg and lead-Tau 400 mg group [(510.9 +/- 57.56) microg/L, (485.40 +/- 98.85) microg/L] were different from those in lead group (P<0.05). (3) The content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), nitric oxide synthase (NOS), acetylcholinesterase (AChE) in brain of lead-Tau 800 mg group and lead-Tau 400 mg group were also different from those in lead group (P<0.05 or P<0.01). The content of GSH and the activity of GSH-Px in lead-Tau 800 mg group were different from those in lead group (P<0.05) as well.</p><p><b>CONCLUSION</b>Taurine could improve learning and memory ability of rats exposed to lead and may play a protective role in brain.</p>
Subject(s)
Animals , Female , Rats , Brain Chemistry , Glutathione , Learning , Long-Term Potentiation , Malondialdehyde , Memory , Neuroprotective Agents , Pharmacology , Organometallic Compounds , Toxicity , Rats, Wistar , Taurine , PharmacologyABSTRACT
To study the chemical components and the antifungal activity of extraction from conidia of Trichoderma viride LTR-2.The extraction were obtained by distilling with Methylene dichloride from conidia of Trichoderma viride LTR-2 cultured on wheat bran solid matrix.Antifungal activity were determined by mycelium growth method.The chemical components of the extraction were analysed by GC-MS,the relative components in the extraction were determined by area normalization.The extraction not only have broad-spectrum control,showed antibiosis against eleven different plant fungal pathogens in PDA dish,such as Rhizoctonia solani,Alternaria brassica,Verticillium dahliae,Macrophoma kawatsukai,Fusarium moniliforme,Botrytis cinerea,Rhizoctonia cerealis,Fusarium oxysporum f.sp.vasinfectum,Bipolaris sorokinana,Fusarium graminearum,Alternaria.mali,but also have high inhibitory effect,and had 89.3% suppressive rate to Rhizoctonia cerealis.About sixty components were separated and identified by GC-MS,majority components were Hydrocarbon,the number of the Hydrocarbon were fourty-three kinds.Ergosterol was the major chemical components of the extract,and has 41.90% content.Other components comprised:Ketone,Organic acid,Alcohol,Ene,et al.Conclusion:The extraction from conidia of Trichoderma viride LTR-2 have antifungal activity.The extration comprised 2H-Pyran-2-one,5,6-dihydro-6-pentyl,it has 2.35% content.reference others literature,2H-Pyran-2-one,5,6-dihydro-6-pentyl may be the suppressive component of the extration.