膜蛋白与膜蛋白组学

膜蛋白是指能够结合或整合到细胞或细胞器的膜上的蛋白质的总称。现在市场上销售的药物80%以上都是作用在膜蛋白上的,膜蛋白是理想的药物靶点,因此,对膜蛋白的研究具有十分重要意义。但由于膜蛋白的溶解、分离、鉴定十分困难,造成膜蛋白组学研究的滞后。本文就膜蛋白的结构,膜蛋白在细胞生理和人类疾病中扮演的重要角色,膜蛋白作为药物靶点的潜力以及膜蛋白组学研究技术作一综述。

Synthesis and Photocatalytic Property of ZnO/TiO2 Inverse Opals Films with Controllable Composition and Topology

A novel method to fabricate composition- （IO） films using a positive sacrificial ZnO and topology-controlled ZnO/TiO2 inverse opals IO template has been developed. This method includes a two-step process, preparation of ZnO IO by a simple electrochemical deposition using a self-assembly polystyrene colloidal crystal template and preparation of ZnO/TiO2 IO by a liquid phase deposition （LPD） process at room temperature. The composition and topology of ZnO/TiO2 IO can be easily controlled by changing the duration of the LPD. After 20 min LPD process, a ZnO/TiO2 composite IO with non-close-packed face-centered cubic air sphere array was obtained. Prolonging the duration to 60 min, a pure TiO2 IO （TIO-LPD60） with obviously thickened walls was formed. The formation mechanism for the compositional and topological variation was discussed. A preliminary study on UV photocatalytic property of the samples for degradation of methylene blue reveals that the composition and topology significantly influenced the photocatalytic activity of the IO film. The ZnO/TiO2 composite IO demonstrates a higher degree of activity than both pure ZnO and pure TiO2 IO, although they have a similar IO wall thickness. Moreover, with increasing IO wall thickness from -52 nm to -90 nm, TIO-LPD60 exhibits the highest level of photocatalytic performance.

EXPRESSION OF PEDF mRNA AND PROTEIN IN NORMAL MOUSE RETINA AND EXPERIMENTAL CHOROIDAL NEOVASCULARIZATION TISSUES

Objective To study the expression of pigment epithelium derived factor (PEDF) in normal mouse retina and experimental choroidal neovascularization (CNV) tissues. Methods CNV mouse models were induced by diode laser. The expression of PEDF mRNA and protein in normal mouse retina and CNV tissues were detected by in situ hybridization and immunohistochemical study. Results In normal mouse retina, PEDF mRNA was observed in the ganglion cell layer, inner nuclear layer and RPE cell layer, and PEDF protein was observed mainly in the nerve fiber layer, ganglion cell layer, photoreceptor cell layer and RPE cell layer, and lower level expression of PEDF protein was also observed in the inner plexiform layer and outer plexiform layer. In CNV tissues, the expression of PEDF mRNA and protein was also observed. 3d and 1 week after photocoagulation, the expression level of PEDF was relatively lower, and increased following the development of CNV. The level was the highest 2 weeks after photocoagulation, then decreased at 3 weeks. Conclusion PEDF was expressed in different layers of retina and was obviously expressed in the CNV tissues induced by laser photocoagulation. These findings suggest that PEDF may participate and modulate the development of CNV.

Cellular stress and redox activity proteins are involved in gastric carcinogenesis associated with Helicobacter pylori infection expressing high levels of thioredoxin-1

Heficobacterpylori infection is related to the development of gastric diseases. Our previous studies showed that high thioredoxin-1 （Trxl） expression in H. pylori can promote gastric carcinogenesis. To explore the underlying molecular mechanisms, we performed an isobaric tags for relative and absolute quantitation （iTRAQ）-based quantitative proteomic analysis of stomach tissues from Mongolian gerbil infected with H. pylori expressing high and low Trxl Differences in the profiles of the expressed proteins were analyzed by bioinformatics and verified using Western blot analysis. We found three candidate proteins, 14-3-3α/β, glutathione-S-transferase （GST）, and heat shock protein 70 （HSP70）, in high Trxl tissues compared with low Trxl tissues and concluded that cellular stress and redox activity- related proteins were involved in the pathogenesis of gastric cancer associated with H. pylori Trxl.

Proteomic study provides new clues for complications of hemodialysis caused by dialysis membrane

The complications of hemodialysis accompanied the hemodialysis and threaten the patients’life.Besides the loss of nutrient substance,such as amino acid and vitamin,we found new clues that the adsorbed proteins on common-used polysulfone-based dialysis membrane might be the reason according to the qualitative proteomic study by ionic liquid assisted sample preparation method.Our results indicated that the adsorbed proteins on the membrane were related with complement activation,blood coagulation,and leukocyte-related biological process.The quantitative proteome further demonstrated some significant changes of signal proteins in the post-dialysis plasma after the hemodialysis,such as beta-2-microglobulin and platelet factor-4,which would further verify these new clues.