Expression, identification and biological effects of the novel recombination protein, PACAP38-NtA, with high bioactivity.

Pituitary adenylate cyclase­activating polypeptide (PACAP) is a type of neuropeptide with multiple biological functions. However, it has a short half­life period in the body, ~3 to 5 min, restricting its further development as a drug that can promote the recovery of nerve injury. In vitro and in vivo experiments have shown that PACAP can repair the epithelial cell on the surface of the injured cornea, as PACAP can act on the trigeminal nerve cell to secrete other active neurotransmitters, which can promote corneal epithelial cell proliferation and differentiation. In the present study, PACAP is connected to the N­terminal agrin domain (NtA) with a genetic engineering method, which allows the function of repairing the injured nerve. Notably, the recombinant polypeptide can interact with laminin, improving the biological effect of PACAP in repairing the injured nerve. In the study, the recombinant protein was constructed by combining PACAP38 and NtA by genetic engineering, and it is expressed in the pronucleus escherichia coli. The recombinant protein, PACAP38­NtA, is obtained with a two­step purification method, including anion­exchange chromatography and Ni­affinity chromatography, with the purity reaching >90%. The in vitro experiment has shown that this recombinant protein not only has the neurotrophy and neural restoration function of PACAP, but also has the function of an anchoring protein as laminin interacts with NtA. According to the in vitro anti­apoptosis, PC12 axon growth and ELISA experiments, this protein has the biological activity of a recombinant protein. PACAP38­NtA also has an anchoring function as NtA and laminin interact with good biological activity.

Homology modeling and molecular docking of human pituitary adenylate cyclase­activating polypeptide I receptor.

Pituitary adenylate cyclase-activating peptide I receptor (PAC1R) is member of the B class of G protein-coupled seven-transmembrane receptors, with molecular functions associated with neural cell differentiation, regeneration and the inhibition of apoptosis. However, the integrity of the protein structure is difficult to be determined in vitro. In the present study, the physicochemical properties of PAC1R were analyzed, the extracellular, transmembrane and intracellular regions were constructed and a three-dimensional structure model of PAC1R was produced using extracellular loop region optimization and the energy minimization homology modeling method. Preliminary studies on the PAC1R protein and ligand interactions used a molecular docking method. The results indicated that the interaction sites of PAC1R were at Ile63, Ser100 and Gln105. These were the sites where the PAC1R combined with a hydrazide small molecule inhibitor. This study provides a theoretical basis for further studies on the model for the development of PAC1R target drugs.

[Technology of advanced glycation endproducts fluorescence measurement and precorrection].

The necessity to measure advanced glycation endproducts (AGE) was analyzed in the present paper, and the apparatus for measuring skin autofluorescence was also designed making use of the special excitation spectrum and emission spectrum. A portion of tissue at the volar side of the arm of individuals (11 diabetes and 19 control subjects) was illuminated with excitation light, i.e., monochromatic light around 370 nm, and the emission spectrum was detected on the skin of control subjects and diabetic patients respectively. All measurements were performed at room temperature in a semi-dark environment. It can be seen that different sites of an individual could lead to different results, and the color can also affect the results. The technology of fluorescence precorrection was applied in order to get rid of the influence of noise, different site of skin, the color of skin etc. The result indicates that the technology of precorrection is of avail and the repetitiveness is well.

[Design of advanced glycation endproducts fluorescence spectrum detecting system].

The method of making use of the technique of fluorescence spectrum to detect advanced glycation endproducts is discussed in the present pape. The emphasis is on the principle and structure of the fluorescence spectrum detecting system. In the end, the authors made use of the system to detect the excitation spectrum at the wavelengths of 365nm, 370nm, 375nm, 380nm and 385nm, respectively, and the authors found that 375nm is the best excitation wavelength. At the same time, the emission spectrum was also detected on the skin of nondiabetic people and patients with diabetes respectively. The result of the experiment indicates that there is a difference distinctly at about 450nm between them, and has proved the feasibility of the system. The detecting system does not need collecting blood sample, is a noninvasive detection technology, and avoids pain and infection to the patients. The process of detection is very rapid and convenient, and the repetitiveness is well. The patient can benefit from it to forecast and diagnose the state of illness such as diabetes, decrepitude and oxidative stress etc conveniently.

[Heavy metals content and pH value in water environment of wild Chinese alligator (Alligator sinensis) habitat: a preliminary study].

In order to reveal the reasons of the dramatic decline of wild Chinese alligator population, an investigation on its habitat status was made across the National Natural Conservation Regions of Chinese alligator in south Anhui Province from 2002 to 2003. Water samples from 21 sites were collected, and their heavy metals (Cu, Zn, Cd and Pb) content and pH value were measured. The results showed that the pH value was 7.84 +/- 0.62, with no significant difference between the waters with and without Chinese alligator, but with significant difference (P< 0.01) among 3 Chinese alligator habitats. In the waters with and without Chinese alligator, no significant difference was observed in the contents of test metals except Pb. The possible pollution source of Pb in wild Chinese alligator habitat was analyzed, which could provide reference for Chinese alligator conservation.

[Vegetation diversity of wild Chinese alligator (Alligator sinensis) habitats].

In June and July of 2003, a field survey on the vegetation of 22 Chinese alligator habitats distributed in Nanling county, Jingxian county, Guangde county, Langxi county and Xuancheng city of Anhui province was conducted, and the plant species of the habitats were recorded and analyzed. The results showed that the vegetation of the whole habitats was secondary, and there were 294 species vascular plants, belonging to 92 families. Pteioblastus amarus shrubbery could be found in all sites, and part differences of the vegetation consisted in different habitats. The relationship between Chinese alligator and habitat vegetation was also analyzed. All of these could offer some basic botanical data for the further protection of the Chinese alligator.