摘要：In view of the bonding angle and the number of neighbouring sites, the hexagonal lattice model is preferred to investigate the designability of protein structures. Here we simulate the designable structures by the simplified HP model in a two-dimensional hexagonal lattice with an unrestricted boundary. The result shows that the structures with a large number of core sites correspond to the high designability and have circular-like profiles. The maximum and average designabilities for the hexagonal lattice model are much higher than those for the square lattice mode, and the maximum and average designabilities for the square lattice model are much higher than those for the triangle lattice model.

摘要：In recent years, immense interest has been paid to the biomolecular architecture with the aim of protein assembly in two di- mensions on solid substrates, and the constructions of clay-protein ultrathin films （CPUFs） are particularly concerned. This paper gives an overview of the recent research concerning the protein molecules （lysozyme, papain, protamine, bovine serum albumin） immobilized on clay mineral （Na-saponite） platelets and assembled in monolayered or multilayered hybrid ultrafilms or nanofilms. Two techniques including alternate layer-by-layer （LbL） assembly and the Langmuir-Blodgett （LB） are de- scribed in detail. A variety of means, including UV-vis absorption, attenuated total reflectance Fourier transform infrared （ATR-FTIR） spectroscopy, XRD, AFM and surface chemistry techniques, have been described for characterization of the films in terms of quantification of protein and clay. The result reveals that electrostatic interaction is a prominent but not the only driving force in CPUF construction. In the case of LB technique, we managed to manipulate the elementary clay mineral platelets （1.3 nm in thickness） and assemble proteins into CPUFs with the aid of surfactants, and the formation of CPUFs was monitored via surface pressure vs. time （a--t） kinetics curves and surface pressure vs. area （a--A） isotherms. The factors that in- fluence protein adsorption on the clay layer, such as surfactants, the concentration of clay, equilibrium time, categories of pro- tein, and injection methods, were investigated. The parameters such as protein amount （nS）, packing density （O）, and average surface area per molecule （.（2） of deposited CPUFs were measured via method of surface chemistry and spectroscopy. By comparing the results of surface chemistry with those of adsorption experiments, we demonstrate that the surface chemistry method is a useful tool in investigating CPUFs. We also found that the water soluble protein molecules could form protein-clay hybrid mon

摘要：Avian influenza, subtype H5N1, causes occasional but serious infections in humans and efforts to produce vaccines against this strain continue. Current influenza vaccines are prophylactic and utilize the two major antigens, hemagglutinin and neuraminidase. Nucleocapsid protein (NP) is an attractive alternative antigen because it is highly conserved across all influenza strains, has been shown to increase the rate of viral clearance, and potential therapeutic vaccines would elicit cytotoxic T lymphocyte responses in an infected person. The NP antigen from H5N1 was characterized using a variety of physico-chemical methods to gain insights into both the biological and physical properties of the antigen which are important from a regulatory viewpoint when considering therapeutic vaccines. Results obtained to date show that NP is relatively unstable and indicate that the conformation of the H5N1 NP antigen is highly dependent upon purification procedure, buffer conditions, pH and the presence or absence of RNA. These factors will need to be clearly defined and taken into consideration when manufacturing and regulating NP vaccine preparations.

摘要：[Objective] The study was to understand the subcellular localization of OsWRKY78 protein in plants. [Method] Primers specific for OsWRKY78 gene were designed according to the OsWRKY78 full length sequence in Genbank. The gene was cloned by RT-PCR method. The gene was then recombined into a plasmid expression vector carrying green fluorescent protein (GFP) gene, pBinGFP. The recombinant was confirmed by PCR and enzyme digestion. The recombinant plasmid pBinGFP-OsWRKY was transformed into Arabidopsis through Agrobacterium tumefaciens strain GV3101 and transgenic plants were obtained. [Result] Measured by fluorescence microscopy, the expression of OsWRKY78 and GFP fusion protein in root tip cells was localized in the nucleus. [Conclusion] This study laid the foundation for further investigating the function of OsWRKY78 gene and its role in related signal transduction and provided theoretical basis for exploring the relation between OsWRKY78 gene and brown planthoppers.

摘要：A thorough understanding of how proteins induce nanoparticle （NP） aggregation is crucial when designing in vitro and in vivo assays and interpreting experimental results. This knowledge is also crucial when developing nano-applications and formulation for drug delivery systems. In this study, we found that extraction of immunoglobulin G （IgG） from cow serum results in lower polystyrene NPs aggregation. Moreover, addition of isolated IgG or fibrinogen to fetal cow serum enhanced this aggregation, thus demonstrating that these factors are major drivers of NP aggregation in serum. Counter-intuitively, NP aggregation was inversely dependent on protein concentration; i.e., low protein concentrations induced large aggregates, whereas high protein concentrations induced small aggregates. protein-induced NP aggregation and aggregate size were monitored by absorbance at 400 nm and dynamic light scattering, respectively. Here, we propose a mechanism behind the protein concentration dependent aggregation; this mechanism involves the effects of multiple protein interactions on the NP surface, surface area limitations, aggregation kinetics, and the influence of other serum proteins.

摘要：The presence of anti-p53 antibody in serum is a biomarker for cancer. However, its high sensitivity detection is still an issue in cancer diagnosis. To tackle this challenge, we used fd phage, a human-safe bacteria-specific virus nanofiber that can be mass-produced by infecting host bacteria in an error-free manner, and genetically engineered it to display a peptide capable of recognizing and capturing anti-p53 antibody on its side wall. We employed the resultant phage nanofibers as a capture probe to develop a modified version of the enzyme- linked immunosorbent assay （ELISA） method, termed phage-ELISA. We compared it to the traditional ELISA method for the detection of anti-p53 antibody, p53-ELISA, which uses recombinant wild-type p53 protein to capture anti-p53 antibody. We applied phage-ELISA to detect anti-p53 antibody in an experimental group of 316 patients with various types of malignant tumors. We found that a detection rate of 17.7% （56 positive cases） was achieved by phage-ELISA, which was comparable to the detection rate of 20.6% for p53-ELISA （65 positive cases）. However, when both phage and p53 were combined to form antibody-capturing probes for phage/p53-ELISA, a detection rate of 30.4% （96 positive cases） was achieved. Our work showed that owing to the combined capture of the anti-p53 antibody by both phage nanofibers and p53, the phage/p53-ELISA achieved the highest diagnostic accuracy and detection efficiency for the anti-p53 antibody in patients with various types of cancers. Our work suggests that a combination of nanofibers and antigens, both of which capture antibody, could lead to increased detection sensitivity, which is useful for applications in the life sciences, clinical medicine, and environmental sciences.

摘要：【目的】trag(transfer gene G)是利用IVIAT(in vivo induced antigen technology)通量筛选鉴定的猪链球菌2型(Streptococcus suis type 2,SS2)感染相关因子,研究该基因在猪链球菌(Streptococcus suis,SS)中的分布情况,研究康复血清与免疫血清在免疫印迹中的反应性有无,间接证明其在体内感染与体外培养时表达差异。【方法】鉴于我国分离株trag与GenBank公布的SS2北美株89/1591的trag序列有95.8%的同源性,据此设计和合成一对检测引物,对SS2我国江苏及四川流行株、其他临床分离株和参考株及SS1、SS1/2、SS9、SS7及C群猪源链球菌共43株进行PCR扩增。另设计一对引物,扩增5株SS代表菌株trag的完整阅读框,并对扩增产物进行测序。据软件分析后,选择TRAG(Transfer protein G)免疫原性良好的区域片段的核酸设计表达引物,PCR扩增后定向克隆至表达载体pET28a(+)构建表达质粒,表达蛋白转印到PVDF膜上,分别与SS2猪康复血清和猪高免血清反应。【结果】trag在SS2中94%(30/32)阳性,SS9中67%(4/6)阳性,SS7阳性,SS1、SS1/2及C群菌阴性。5株细菌TRAG的氨基酸序列与SS2中国株98HAH33、05ZYH33及北美株89/1591同源性>97%。所获得重组蛋白只能被康复血清识别。【结论】从SS致病株中检出感染相关基因trag,提示该基因可能与SS致病性有关,重组蛋白的免疫转印结果表明,TRAG可能与SS2体内感染相关。

摘要：目的:观察温肾方治疗乙肝肝硬化合并肝性脑病肾阳虚证患者的临床疗效及其对高迁移率族蛋白B1(high mobility group protein B1,HMGB1),Toll样受体4(Toll-like receptor 4,TLR4)含量的影响。方法:纳入成都中医药大学附属医院2013年8月至2015年1月收治的66例乙肝肝硬化合并肝性脑病患者。采用前瞻性、平行对照方法设计,将纳入的66例患者按1∶1分为治疗组和对照组,每组各33例。对照组给予常规内科综合治疗、结肠透析和安慰剂灌肠。治疗组给予常规内科综合治疗、结肠透析和温肾方灌肠。疗程均为10日。治疗前后分别检测患者肝功能水平、数字连接试验(number connect test,NCT)时间、数字符号试验(digit-symbol test,DST)评分及血氨水平,外周血HMGB1,TLR4含量。治疗结束后,分别计算两组患者清醒时间及总有效率。结果:两组患者基线具有可比性。治疗结束后,治疗组总有效率优于对照组(P <0. 05)。治疗组在血氨下降幅度,肝功能恢复程度,NCT时间下降幅度,SDT评分增加程度以及患者清醒时间缩短幅度等方面均优于对照组(P <0. 05)。治疗结束后,治疗组外周血HMGB1,TLR4含量低于对照组(P <0. 05)。结论:温肾方可显著提高乙肝肝硬化合并肝性脑病肾阳虚证患者的临床疗效,其作用机制可能与抑制HMGB1,TLR4含量,进而抑制炎症因子释放,降低血氨水平有关。

摘要：目的探讨一定剂量X线照射对大鼠压迫型脊髓损伤模型组织结构及功能恢复的影响。方法采用动脉瘤夹建立大鼠压迫型脊髓损伤模型,70只SpragueDawley大鼠均接受T2节段的脊髓损伤,然后被随机分为2组,照射组在损伤后14d接受X线照射,对照组则不接受任何治疗。所有大鼠分别在脊髓损伤后第3、7、14、21、28、35和42天接受后肢运动及斜板测定,43d将所有实验大鼠处死后取出脊髓损伤标本,进行组织学检查。结果70只实验鼠中符合设计要求的共62只,其中照射组32只,对照组30只。X线照射组大鼠的后肢运动恢复及斜板测定均明显优于对照组,两者之间的差异有统计学意义(P<0.01)。照射组大鼠脊髓损伤部位的水肿及坏死区域明显少于对照组,胶质原纤维酸性蛋白(glialfibrillaryacidicprotein,GFAP)阳性细胞数明显少于对照组,而神经元数目则明显多于对照组。结论一定剂量X线照射可以改善脊髓损伤区的组织结构并促进大鼠脊髓损伤后运动功能的恢复。

摘要：目的:通过构建抗TNF-αFab重组表达质粒,在大肠杆菌周质空间中高效可溶性表达抗TNF-α Fab,经工艺优化以提高目的蛋白的产率。方法:菌体经发酵罐发酵后,使用萃取方法进行周质空间可溶性目的蛋白的萃取并通过试验设计(DOE)优化萃取工艺,采用Q Sepharose Fast Flow强碱性阴离子交换柱净化,Phenyl Sepharose Fast Flow疏水柱及protein L亲和柱纯化。结果:经DOE筛选得到了相对最优的萃取条件,该纯化方法得到的目的蛋白的体积产率可达23.5mg/L,纯度大于90%,回收率大于24%,且离子交换柱净化过程有效地保护了亲和柱,提高了亲和柱的使用寿命。抗体亲和力检测证明抗TNF-α Fab具有良好的生物学活性。结论:通过萃取工艺及纯化方法的优化,为抗TNF-α Fab的进一步工艺放大及目的蛋白的性质研究奠定了基础。