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Separation and purification of hypocrellin A (HA) and hypocrellin B (HB) are conducted for extracted concentrated solution of hypocrellin through dry packing of molecularly imprinted polymers (MIPs) of hypocrellin A and B and preparative solid phase extraction column. The result shows that the optimum packing column combination for mixed adsorption is H5 (i.e. MIP of hypocrellin A and B are respectively 10.5g and 4.5g), and that the elution sequence is hypocrellin A elution first and then hypocrellin B elution next after the eluent is changed.

Insulin is essential for maintaining glucose homeostasis and is synthesized and secreted almost exclusively from pancreatic β-cells in the islets of Langerhans. The analysis of rat insulin2 promoter sequences indicates that it has pancreatic and duodenal homeobox factor-1 (PDX-1) binding site. In mature β-cells, PDX-1 transactivates the insulin and other genes involved in glucose sensing and metabolism. The function of PDX-1 can be regulated by post-translational modifications. Sumoylation plays an important role in regulating numerous physiological and pathological processes through altering the function of its target proteins. In this paper, to understand the function and transcription activities of insulin gene promoter, we constructed rat insulin 2 promoter (RIP II). Then we investigated whether sumoylation of PDX-1 activated this promoter transcription by luciferase reporter assay in HepG-2 cells. Results indicated that sumoylation enhanced PDX-1 activity for the insulin gene promoter transcription.

NF-H (a member of neurofilaments) is a protein widely expressed in all kinds of neurons after birth and can be used as one of the symbols of mature neurons. Constuction of NF-H promoter luciferase reporter plasmid will provide the theory basis for researching the effect of other transcription factors on regulating NF-H transcription. Here, human NF-H promoter luciferase reporter plasmid were successfully constructed. Then the effects of some key transcription factors were investigated by luciferase reporter assays in COS-7 cells. The results showed that retinoid X receptor α (RXRα) can enhance transcriptional activity of NF-H. Furthermore, ERK 1/2 (extracellular signal-regulated kinase 1/2) and STAT3 (signal transducer and activator of transcription 3) also show obvious impact in activating NF-H transcription.

Aquaporins (AQPs), a family of water channels, function as a water-selective transporting protein in cell membranes. Aquaporin 1 (AQP1) was first discovered in human erythrocytes as a water channel for high osmotic water permeability. AQP1 promoter is responsible for regulation of its transcription and expression. In this study, molecular biology and genetic engineering knowledge and principles of construction of AQP1 promoter plasmid, and recombinant plasmids were identified and measured for luciferase, for promoter function. Our study successfully constructed AQP1 promoter luciferase reporter gene expression plasmid and successfully carry out the functions of its detection, provides a new foundation for the transcription expression and function regulation of the AQP1

Based on observations that lactic acid bacteria has proved to be beneficial in the treatment of viral-and antibiotic-associated diarrhea but the mechanisms of action remain unknown. Some reports indicated that nitric oxide (NO) might be involved in the protective mechanisms in the gastrointestinal tract and may contribute to some of the beneficial effects of probiotics. To confirm the effect of a probioticLactobacillus acidophilus(L. acidophilus) strain TCCC 11036 on the NO synthesis, in the present study, HepG2 human liver cells were cultured and treated with the supernatant or precipitate ofL. acidophilusTCCC 11036 cell hydrolysates, then NO synthesis and its regulation were measured with the methods of NO assay, luciferase reporter assay and RT-PCR. The results showed that the production of nitric oxide was increased after treated with precipitates of the bacterium, and its transcription was enhanced as well. These works might provide a foundation for the following study ofL. acidophilusand its probiotics functions, and contribute to the development of functional foods or drugs that provide health benefits to patients suffering from inflammation, cardiovascular disease, or some other diseases correlated with NO.

Plectasin, a novel antimicrobial peptide, is isolated from a saprophytic fungus Pseudoplectania nigrella. Plectasin showed potent antibacterial activity in vitro against Gram-positive, especially the Streptococcus pneumoniae and Streptococcus pneumoniae, including strains resistant to conventional antibiotics. In our previous study, plectasin had been expressed at a high yield as a thioredoxin (Trx) – fused protein in Escherichia coli. However, it couldn’t exhibit the antimicrobial activity unless the Trx-tag had been cleaved, which made the producing process be complicated. Concerning that plectasin has no complex post-translational modification and toxicity on E. coli, on the basis of the former works, we further establish the independent and tandem expression system of plectasin in E. coli. In the present study, the coding sequence of plectasin was obtained from pET32a-PLEC with four primers to amplify the independent and tandem plectasin fragments by overlapping PCR-based gene synthesis, and then cloned into pET22b (+) vector. The recombinant protein was expressed successfully in E. coli with IPTG induction. These works might throw light on the production or study of plectasin, and contribute to the development of novel anti-infectious drugs in the future.

In this paper, a strain HZ1 which was isolated in our former works was classified as Lactobacillus Casei (L. Casei) by 16S rDNA sequence analysis. The results of angiotensin-converting enzyme (ACE) inhibitory assay showed that this novel stain was able to produce ACE inhibitory components when it was used to fermented milk. Applying the methods of membrane filtration and anion-exchange chromatography with fast protein liquid chromatography (FPLC) system, nine fractions with remarkable ACE inhibitory activity were obtained, and two bioactive fractions, recorded as ACEI-2 and ACEI-5, exhibited the highest ACE inhibitory rate of 60.55% and 71.71%, respectively. Furthermore, seven fractions proteins/polypeptides, which exhibited ACE inhibitory rate higher than 50% were separated from ACEI-2 and ACEI-5 by using sephadex gel filtration chromatography. These works might provide a foundation for the following study of L. Casei HZ1 and its probiotics functions, and contribute to the development of functional foods or drugs that provide health benefits to patients suffering from hypertension.