ABSTRACT
Parkinson's disease (PD) is a kind of senile neurodegenerative disease. Dopaminergic drugs and anticholinergic drugs are the two major therapeutic drugs for PD. In the past several decades, great progress has been achieved on dopamines (DAs) and their synergists including monoamine oxidase B (MAO-B) inhibitors, catechol oxygen methyl transferase inhibitors, ergot and nonergot DA receptor agonists, DA precursor drugs, cannabis and isatin. Isatin is the inhibitor of endogenous specific anti-aging enzyme MAO-B, which has a variety of pharmacological activities. Moreover, the pharmacological mechanism of isatin may be associated with the regulatory functions of various protein activities.
ABSTRACT
Cutinase can degrade aliphatic and aromatic polyesters, as well as polyethylene terephthalate. Lack of commercially available cutinase calls for development of cost-effective production of efficient cutinase. In this study, eight cutinase genes were cloned from Sclerotinia sclerotiorum. The most active gene SsCut-52 was obtained by PCR combined with RT-PCR, expressed in Escherichia coli BL21 and purified by Ni-NTA affinity chromatography to study its characteristics and pathogenicity. Sscut-52 had a total length of 768 bp and 17 signal peptides at the N terminals. Phylogenetic analysis showed that its amino acid sequence had the highest homology with Botrytis keratinase cutinase and was closely related to Rutstroemia cutinase. Sscut-52 was highly expressed during the process of infecting plants by Sclerotinia sclerotiorum. Moreover, the expression level of Sscut-52 was higher than those of other cutinase genes in the process of sclerotia formation from mycelium. The heterologously expressed cutinase existed in the form of inclusion body. The renatured SsCut-52 was active at pH 4.0-10.0, and mostly active at pH 6.0, with a specific activity of 3.45 U/mg achieved. The optimum temperature of SsCut-52 was 20-30 ℃, and less than 60% of the activity could be retained at temperatures higher than 50 ℃. Plant leaf infection showed that SsCut-52 may promote the infection of Banlangen leaves by Sclerotinia sclerotiorum.
Subject(s)
Ascomycota/genetics , Carboxylic Ester Hydrolases , Cloning, Molecular , PhylogenyABSTRACT
We cloned flavonol synthase gene (named as CmFLS) by RACE from Chrysanthemum morifolium cv. 'Hangju' based on transcriptome database. Sequencing results showed that 1 235 bp sequence was acquired with the largest open reading frame (ORF) of 1 008 bp, which encoded 335 amino acids. The predicted CmFLS encoded protein had an isoelectric point (pI) of 5.41. The phylogenetic tree analysis indicated that CmFLS was highly homologous to other FLSs, which identified from the species of Compositae. The recombinant fusion protein, with a molecular mass of 43 kDa, was successfully expressed by prokaryotic expression system. Meanwhile, Ni-NTA resin was used to purify the recombinant fusion protein, and the Ni-Native Buffer containing 250 mmol·L⁻¹ imidazole was most favorable for elution. The purified recombinant fusion protein was subjected to in vitro catalytic reaction, and then the products were extracted and analyzed by HPLC. The results showed that the recombinant fusion protein CmFLS was able to catalyze the production of quercetin by dihydroquercetin under specific buffer and reaction conditions, which indicated that the functional protein encoded by CmFLS had dioxygenase activity in the biosynthetic pathway of flavonoids biosynthesis in Ch. morifolium cv. 'Hangju'. The above results laid the foundation for further studying on CmFLS, and provided new ideas for the regulation of flavonoids metabolism from the molecular level and the catalytic synthesis of flavonols in vitro.