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1.
日本血吸虫脂肪酸结合蛋白基因的克隆及其在大肠杆 … 总被引:3,自引:2,他引:3
用PCR法从日本血吸虫中国大陆株成虫cDNA文库中快速克隆出一大小为600bp左右的DNA片段,DNA序列分析证实,所扩增到的DNA片段中含有日本血吸虫脂肪酸结合蛋白(Sj-14FABPc)基因,将该基因重组到表达型质粒pGEX-2T中,表达的GST融合蛋白分子量是41kD,用谷胱甘肽琼脂糖凝胶亲和层析柱纯化的重组蛋白不仅纯度好,而且得率高,纯化产量可达25mg/L培养物,免疫试验结果表明该重组蛋 相似文献
2.
日本血吸虫脂肪酸结合蛋白基因的克隆及其在大肠杆菌中的表达 总被引:5,自引:0,他引:5
用PCR法从日本血吸虫中国大陆株成虫cDNA文库中快速克隆出一大小为600bp左右的DNA片段,DNA序列分析证实,所扩增到的DNA片段中含有日本血吸虫脂肪酸结合蛋白(Sj-14FABPc)基因,将该基因重组到表达型质粒pGEX-2T中,表达的GST融合蛋白分子量是41kD,用谷胱甘肽琼脂糖凝胶亲和层析柱纯化的重组蛋白不仅纯度好,而且得率高,纯化产量可达25mg/L培养物,免疫试验结果表明该重组蛋白具有良好的抗原性,为其用作疫苗分子创造了条件。 相似文献
3.
用PCR法扩增出编码人FAS分子胞外区的cDNA片段,直接克隆到pGEM-T载体上,经DNA序列测定后,再插入到谷胱甘肽转硫酶(GST)融合蛋白表达载体pGEX-KG的EcoRⅠ和SalⅠ位点之间,构成重组质粒pKG-hFAS,将此质粒导入大肠杆菌,经IPTG诱导后获得GST-hFAS重组融合蛋白的表达,用谷胱甘肽偶联的Sepharose4B经亲合层析获得纯化的GST-hFAS蛋白,经凝血酶酶切和二次亲合层析去除GST部分,得到纯化的FAS蛋白.用纯化的FAS抗原免疫家兔制备了抗FAS抗体,经检测发现抗FAS抗体能诱导U937细胞发生细胞凋亡 相似文献
4.
小麦丛矮病毒NS蛋白基因的克隆及序列分析 总被引:2,自引:2,他引:0
利用与N蛋白mRNA3'末端顺序相同的20寡聚核苷酸引物,通过点杂交、限制性内切酶分析从小麦丛矮病毒(WRSV)cDNA文库中筛选到编码N蛋白基因下游顺序的cDNA克隆。序列分析表明,该cDNA片段含有一编码的40kD蛋白的开放读框。将该读框的全长cDNA经PCR扩增后,克隆到pGEX-3X上,在大肠杆菌DE3中用IPTG诱导表达,经蛋白质印迹鉴定,该基因为小麦丛矮病毒NS蛋白基因。 相似文献
5.
日本血吸虫中国大陆株TPI基因的克隆及其表达产物特性 总被引:2,自引:2,他引:2
磷酸丙糖异构酶(TPI)是血吸虫病疫苗重要的候选抗原基因之一。参考日本血吸虫已发表的TPIcDNA序列,以日本血吸虫中国大陆株成虫mRNA为模板,用RT-PCR法快速克隆出一大小约800bp的DNA片段。DNA序列分析证实,所扩增到的DNA片段即为日本血吸虫中国大陆株磷酸丙糖异构酶(SjTPIc)基因。将该基因重组到表达型质粒pGEX-4T中,表达的GST融合蛋白分子量约54kD。用谷胱甘肽琼脂糖凝胶亲和层析柱纯化的重组蛋白不仅纯度好,而且得率高,纯化产量可达30mg/L培养物。免疫试验结果表明该重组蛋白具有良好的抗原性,是一种较为理想的抗原分子。 相似文献
6.
以日本血吸虫mRNA为模板,用RTPCR法快速克隆到一大小约600bp的DNA片段,DNA序列分析证实,所扩增到的DNA片段中含有日本血吸虫226膜相关蛋白(Sj226(Ch))基因,将该基因重组到表达型质粒pGEX4T中,表达的GST融合蛋白分子量约48kD,用谷胱甘肽琼脂糖凝胶亲和层析柱纯化的重组蛋白不仅纯度好,而且得率高,纯化产量可达40mg/L培养物,免疫试验结果表明该重组蛋白具有良好的抗原性,为其在血吸虫病抗感染中的免疫作用研究创造了条件。 相似文献
7.
天麻抗真菌蛋白GAFP—Ⅰ的一级结构和cDNA克隆 总被引:10,自引:0,他引:10
天麻抗真菌蛋白GAFP-Ⅰ是从天麻顶生球茎分离的14kD蛋白,它能强烈抑制腐生真菌菌丝的生长,在天麻限制和防止密环菌侵染球茎的防卫机制中起重要作用。本文报告GAFP-I的一级结构和cDNA克隆的核苷酸序列。首先测得N-末端7个氨基酸序列为SDRLNSG-用以合成 一个简并引物,由天麻营养球茎提取RNA,通过3‘-RACE技术扩增到一个600bp的cDNA片段,直接克隆到pGE-T载体中测定核苷酸序 相似文献
8.
利用突变的绿色荧光蛋白基因为标记构建新型克隆载体 总被引:3,自引:0,他引:3
将三位点替换突变的绿色荧光蛋白(GFP_S65T、V68L、S72A)基因插入到pBluescriptSK(+)的XbaⅠ和SacⅠ之间,构建为新型的克隆载体pGreenLD。此质粒载体在E.coli中表达后使菌落在日光下呈现黄绿色,而在长波紫外光照射下呈现亮绿荧光,当外源DNA片段插入该载体的多克隆位点使gfp基因表达受阻时,转化的E.coli菌落为白色。因此可以用E.coli菌落黄绿色/绿色荧光的消失作为检测指标来筛选含有重组质粒的克隆。 相似文献
9.
水稻矮缩病毒基因组第八号片段的cDNA克隆序列分析及在大肠杆菌中的表达 总被引:6,自引:0,他引:6
从水稻矮缩病毒(RDV)中国福建分离物中分离出基因组第八号片段dsRNA,经逆转录合成cDNA,应用聚合酶链式反应技术扩增了编码区cDNA,并克隆在pGEM3Zf(一)载体上。该片段编码病毒外层外壳蛋白。对重组子进行限制性内切酶分析,亚克隆及全序列测定,结果表明,克隆片段全长1356bp,含有一个1266bp的阅读框架,编码一个含421个氨基酸的多肽。与日本流行株相应片段比较,有核苷酸和氨基酸水平 相似文献
10.
日本血吸虫中国大陆株22.6kD膜相关蛋白基因的克隆及其在大肠杆菌?… 总被引:1,自引:0,他引:1
以日本血吸虫mMRA为模板,用RT-PCR法快速克隆到一大小约600bp的DNA片段,DNA序列分析证实,所扩增到的DNA片段中含有日本血吸虫22.6膜相关蛋白基因,将该基因重组到表达型质粒pGEX-4T中,表达的GST融合蛋白分子量约48kD,用谷胱甘肽琼脂糖凝胶亲和层析柱纯化的重组蛋白不仅纯度好,而且得率高,纯化产量可达40mg/L培养物,免疫试验结果表明该重组蛋白具有良好的抗原性,为其在血吸 相似文献
11.
Symmetric primary and tertiary structure mutations within a symmetric superfold: a solution, not a constraint, to achieve a foldable polypeptide 总被引:1,自引:0,他引:1
Brych SR Dubey VK Bienkiewicz E Lee J Logan TM Blaber M 《Journal of molecular biology》2004,344(3):769-780
In previous studies designed to increase the primary structure symmetry within the hydrophobic core of human acidic fibroblast growth factor (FGF-1) a combination of five mutations were accommodated, resulting in structure, stability and folding kinetic properties similar to wild-type (despite the symmetric constraint upon the set of core residues). A sixth mutation in the core, involving a highly conserved Met residue at position 67, appeared intolerant to substitution. Structural analysis suggested that the local packing environment of position 67 involved two regions of apparent insertions that distorted the tertiary structure symmetry inherent in the beta-trefoil architecture. It was postulated that a symmetric constraint upon the primary structure within the core could only be achieved after these insertions had been deleted (concomitantly increasing the tertiary structure symmetry). The deletion of these insertions is now shown to permit mutation of position 67, thereby increasing the primary structure symmetry relationship within the core. Furthermore, despite the imposed symmetric constraint upon both the primary and tertiary structure, the resulting mutant form of FGF-1 is substantially more stable. The apparent inserted regions are shown to be associated with heparin-binding functionality; however, despite a marked reduction in heparin-binding affinity the mutant form of FGF-1 is surprisingly approximately 70 times more potent in 3T3 fibroblast mitogenic assays. The results support the hypothesis that primary structure symmetry within a symmetric protein superfold represents a possible solution, rather than a constraint, to achieving a foldable polypeptide. 相似文献
12.
The biophysical study of protein-protein interactions and docking has important implications in our understanding of most complex cellular signaling processes. Most computational approaches to protein docking involve a tradeoff between the level of detail incorporated into the model and computational power required to properly handle that level of detail. In this work, we seek to optimize that balance by showing that we can reduce the complexity of model representation and thus make the computation tractable with minimal loss of predictive performance. We also introduce a pair-wise statistical potential suitable for docking that builds on previous work and show that this potential can be incorporated into our fast fourier transform-based docking algorithm ZDOCK. We use the Protein Docking Benchmark to illustrate the improved performance of this potential compared with less detailed other scoring functions. Furthermore, we show that the new potential performs well on antibody-antigen complexes, with most predictions clustering around the Complementarity Determining Regions of antibodies without any manual intervention. 相似文献
13.
《Expert review of proteomics》2013,10(1):13-26
Exploring the function of the genome and the encoded proteins has emerged as a new and exciting challenge in the postgenomic era. Novel technologies come into view that promise to be valuable for the investigation not only of single proteins, but of entire protein networks. Protein microarrays are the innovative assay platform for highly parallel in vitro studies of protein–protein interactions. Due to their flexibility and multiplexing capacity, protein microarrays benefit basic research, diagnosis and biomedicine. This review provides an overview on the basic principles of protein microarrays and their potential to multiplex protein–protein interaction studies. 相似文献
14.
Dimo Kashchiev 《Proteins》2014,82(9):2229-2239
15.
A previously developed computer program for protein design, RosettaDesign, was used to predict low free energy sequences for nine naturally occurring protein backbones. RosettaDesign had no knowledge of the naturally occurring sequences and on average 65% of the residues in the designed sequences differ from wild-type. Synthetic genes for ten completely redesigned proteins were generated, and the proteins were expressed, purified, and then characterized using circular dichroism, chemical and temperature denaturation and NMR experiments. Although high-resolution structures have not yet been determined, eight of these proteins appear to be folded and their circular dichroism spectra are similar to those of their wild-type counterparts. Six of the proteins have stabilities equal to or up to 7kcal/mol greater than their wild-type counterparts, and four of the proteins have NMR spectra consistent with a well-packed, rigid structure. These encouraging results indicate that the computational protein design methods can, with significant reliability, identify amino acid sequences compatible with a target protein backbone. 相似文献
16.
Paula M. Dalessio Rebecca C. Craven Parvez M. Lokhandwala Ira J. Ropson 《Proteins》2013,81(2):316-325
An infective retrovirus requires a mature capsid shell around the viral replication complex. This shell is formed by about 1500 capsid protein monomers, organized into hexamer and pentamer rings that are linked to each other by the dimerization of the C‐terminal domain (CTD). The major homology region (MHR), the most highly conserved protein sequence across retroviral genomes, is part of the CTD. Several mutations in the MHR appear to block infectivity by preventing capsid formation. Suppressor mutations have been identified that are distant in sequence and structure from the MHR and restore capsid formation. The effects of two lethal and two suppressor mutations on the stability and function of the CTD were examined. No correlation with infectivity was found for the stability of the lethal mutations (D155Y‐CTD, F167Y‐CTD) and suppressor mutations (R185W‐CTD, I190V‐CTD). The stabilities of three double mutant proteins (D155Y/R185W‐CTD, F167Y/R185W‐CTD, and F167Y/I190V‐CTD) were additive. However, the dimerization affinity of the mutant proteins correlated strongly with biological function. The CTD proteins with lethal mutations did not dimerize, while those with suppressor mutations had greater dimerization affinity than WT‐CTD. The suppressor mutations were able to partially correct the dimerization defect caused by the lethal MHR mutations in double mutant proteins. Despite their dramatic effects on dimerization, none of these residues participate directly in the proposed dimerization interface in a mature capsid. These findings suggest that the conserved sequence of the MHR has critical roles in the conformation(s) of the CTD that are required for dimerization and correct capsid maturation. Proteins 2013. © 2012 Wiley Periodicals, Inc. 相似文献
17.
The heat capacity plays a major role in the determination of the energetics of protein folding and molecular recognition. As such, a better understanding of this thermodynamic parameter and its structural origin will provide new insights for the development of better molecular design strategies. In this paper we have analyzed the absolute heat capacity of proteins in different conformations. The results of these studies indicate that three major terms account for the absolute heat capacity of a protein: (1) one term that depends only on the primary or covalent structure of a protein and contains contributions from vibrational frequencies arising from the stretching and bending modes of each valence bond and internal rotations; (2) a term that contains the contributions of noncovalent interactions arising from secondary and tertiary structure; and (3) a term that contains the contributions of hydration. For a typical globular protein in solution the bulk of the heat capacity at 25°C is given by the covalent structure term (close to 85% of the total). The hydration term contributes about 15 and 40% to the total heat capacity of the native and unfolded states, respectively. The contribution of non-covalent structure to the total heat capacity of the native state is positive but very small and does not amount to more than 3% at 25°C. The change in heat capacity upon unfolding is primarily given by the increase in the hydration term (about 95%) and to a much lesser extent by the loss of noncovalent interactions (up to ~5%). It is demonstrated that a single universal mathematical function can be used to represent the partial molar heat capacity of the native and unfolded states of proteins in solution. This function can be experimentally written in terms of the molecular weight, the polar and apolar solvent accessible surface areas, and the total area buried from the solvent. This unique function accurately predicts the different magnitude and temperature dependences of the heat capacity of both the native and unfolded states, and therefore of the heat capacity changes associated with folding/unfolding transitions. © 1995 Wiley-Liss, Inc. 相似文献
18.
蛋白质相互作用研究的新技术与新方法 总被引:2,自引:0,他引:2
目前,蛋白质相互作用已成为蛋白质组学研究的热点. 新方法的建立及对已有技术的改进标志着蛋白质相互作用研究的不断发展和完善.在技术改进方面,本文介绍了弥补酵母双杂交的蛋白定位受限等缺陷的细菌双杂交系统;根据目标蛋白特性设计和修饰TAP标签来满足复合体研究要求的串联亲和纯化技术,以及在双分子荧光互补基础上发展的动态检测多个蛋白质间瞬时、弱相互作用的多分子荧光互补技术.还综述了近两年建立的新方法:与免疫共沉淀相比,寡沉淀技术直接研究具有活性的蛋白质复合体;减量式定量免疫沉淀方法排除了蛋白质复合体中非特异性相互作用的干扰;原位操作的多表位-配基绘图法避免了样品间差异的影响,以及利用多点吸附和交联加固研究弱蛋白质相互作用的固相蛋白质组学方法. 相似文献
19.
Protein-fusion constructs have been used with great success for enhancing expression of soluble recombinant protein and as tags for affinity purification. Unfortunately the most popular tags, such as GST and MBP, are large, which hinders direct NMR studies of the fusion proteins. Cleavage of the fusion proteins often re-introduces problems with solubility and stability. Here we describe the use of N-terminally fused protein G (B1 domain) as a non-cleavable solubility-enhancement tag (SET) for structure determination of a dimeric protein complex. The SET enhances the solubility and stability of the fusion product dramatically while not interacting directly with the protein of interest. This approach can be used for structural characterization of poorly behaving protein systems, and would be especially useful for structural genomics studies. 相似文献
20.
Improvement of protein stability in protein microarrays 总被引:1,自引:0,他引:1
Protein stability in microarrays was improved using protein stabilizers. PEG 200 at 30% (w/v) was the most efficient stabilizer giving over 4-fold improvement in protein stability compared to without the stabilizer. PEG 200 above 10% (w/v) in the array solution prevented the evaporation of water in the sample and thereby improved protein stability in the microarray. When the streptavidin-biotin binding reaction was performed under optimized conditions, biotin-BSA-fluorescein isothiocyanate (FITC) was detected from 1 ng ml–1 to 5 g ml–1 by fluorescence analysis. 相似文献