The construction and cloning of synthetic genes coding for artificial proteins and expression studies to obtain fusion proteins

Synthetic genes coding for artificial proteins with predeflnedand nutritionally valuable amino acid compositions have beenconstructed and cloned In bacterial plasmid vector pKK233-2.The genes were constructed from three easily interchangeable‘cassettes’ encoding either essential, non-essentialor branched-chain amino acid residues. A potential hairpin loopstructure in the mRNA around the region of the ribosome bindingsite was probably the reason for blockage of translation fromthis vector. Two selected genes, AHB (containing one copy ofeach cassette) and A (consisting of six copies concatemerizedA₆cassette) were cloned into pUR300, a (ß-Gal fusionvector and expressed as fusion proteins (ß-Gal-AHBand (ß-Gal-A₆.     

建筑橡胶基防水材料新进展及建议

一、国外建筑防水材料1.概况欧洲的屋面防水材料主要包括改性沥青卷材、单层聚合物片材及氧化沥青油毡三大类,其中,改性沥青约占65%,占统治地位;单层聚合物片材约占24%,呈持续增长之势;氧化沥青油毡下降到7%,呈迅速减少之势。改性沥青防水卷材主要包括SBS和APP改性沥青卷材两类,弹性体(SBS)改性沥青卷材的用量多于塑性体(APP)改性沥青卷材。在欧洲的单层聚合物片材中,目前PVC片材仍占主导地位,但EPDM(乙丙橡胶)片材则稳定地占有一定的比例;特别值得指出的是,TPO(热塑性聚烯烃)片材发展很快,2001年在屋面市场中已达到672万平方米(约…     

Permuteins of interleukin 1{beta}--a simplified approach for the construction of permutated proteins having new termini

A technique for the rapid and simple generation of permutatedversions of the interleukin-1ß (IL-1ß) geneis described. In this method, the human IL-1ß cDNAis twice amplified by the polymerase chain reaction (PCR) andthe resulting DNA fragments are ligated in tandem. Between thetwo genes, the DNA sequence encodes a short four amino acidloop to link the native N- and C-terminal ends of the IL-1ßprotein. By using PCR amplification from this starting template,a new version of the IL-1ß cDNA was obtained thatencodes a permutated form of the IL-1ß protein wherethe new N- and C-terminal amino acids correspond to residues65 and 64 of the native IL-1ß sequence, respectively.The name ‘permutein’ is proposed to describe proteinsgenerated by this technology. The molecular profile (IL-1 receptorbinding, biologic activity and solution properties) of the IL-1permutein produced by this technology, permutein 65/64, is shownto be identical to that of native IL-1ß The approachshould be useful to define further the structural features ofthis protein that are important for its function.     

A three-step PCR protocol for construction of chimeric proteins

A general method is described for creating chimeric proteins by transposition of subdomain-sized gene fragments. The method uses three sequential PCR steps to circumvent several limitations inherent in transposition of small insertions and has been optimized to avoid purification of intermediate products. The sequence-independence of the method permits flexibility in the choice of host molecule and insertion site.      

建筑橡胶基防水材料新进展及建议(续)

3.科技创新取得进展(1)产品标准和规范。2004年制定和修订了大量防水材料产品标准和技术规范、规程。这些标准和规范的制定和修订对提高我国建筑防水技术水平、规范防水材料市场起到积极的促进作用。2004年制定和修订的产品标准和规范见表3。(2)产业政策。①建设部发布227号文件《关于加强建筑防水材料生产与应用管理工作的意见》,重新确定了建筑防水材料发展目标和技术路线;大力发展弹性体(SBS)、塑性体(APP)改性防水卷材,积极推行高分子防水卷材,努力发展环保型防水涂料。研究开发高档建筑密封材料、地下工程防水材料、城市桥梁工程防…     

三化法安装悬索管道跨越索具及管桥施工技术

介绍在靖咸长输管道施工中 ,针对在 6 0km的线路内出现 18个悬索跨越 ,跨越集中且数量多的情况 ,采用的悬索跨越“数据处理电算化、索具预制工厂化、安装作业流水化”的“三化法”施工技术 ,悬索跨越的安装工期仅用时 2 0余天 ,且施工质量优良     

开发新型肥料与建设现代农业

开发新型肥料、提升科学施肥水平是建设现代农业的一个重要组成部分。新型肥料的技术内涵是:有效成分的高利用率;绿色环保;低的生产成本和农民可以接受的销售价格。     

Interactive construction of residue-based diagrams of proteins: the RbDe web service

We announce the Residue-based Diagram Editor (RbDe) web servicethat allows online construction of residue-based diagrams andthe creation of stored diagram libraries. The service has beentuned for the construction of snake-like diagrams (for transmembraneproteins) but can be used to render any protein for which definedsecondary structure data or hypotheses are available. RbDe isfreely available through the Internet from our web site: http://transport.physbio.mssm.edu/rbde/RbDe.html.Licenses for intranet uses can be obtained upon request.     

PVC wood: A new look in construction

As a result of the increasing environmental concern for forest protection, there is a rapidly growing demand for alternatives to wood products. PVC wood, which includes PVC foam and PVC/wood flour composite, shows improved performance over wood in the following properties: termite resistance, weathering aging, less moisture absorption, and ease of installation. It can be nailed, screwed, sawed, cut, and glued like wood by conventional tools without any special skills required. Although the bending strength of PVC wood is lower, it can be used for decorative applications, i.e., cornice, door, and siding.     

A new approach to the design of stable proteins

We propose a simple algorithm to design a sequence which fitsa given protein structure with a given energy. The algorithmis a modification of the Metropolis Monte Carlo scheme in sequencespace with an evolutionary temperature which sets the energyscale. There is a one to one correspondence between this optimizationscheme and the Ising model of ferromagnetism. This analogy impliesthat the design algorithm does not encounter multiple-minimaproblems and is very fast. The algorithm is tested by ‘predicting’the primary structures of four proteins. In each case the calculatedprimary structures had statistically significant homology withthe natural structures.     

Using synthetically modified proteins to make new materials

The uniquely diverse structures and functions of proteins offer many exciting opportunities for creating new materials with advanced properties. Exploiting these capabilities requires a set of versatile chemical reactions that can attach nonnatural groups to specific locations on protein surfaces. Over the years, we and others have developed a series of new techniques for protein bioconjugation, with a particular emphasis on achieving high site selectivity and yield. Using these reactions, we have been able to prepare a number of new materials with functions that depend on both the natural and the synthetic components. In this Account, we discuss our progress in protein bioconjugation over the past decade, focusing on three distinct projects. We first consider our work to harness sunlight artificially by mimicking features of the photosynthetic apparatus, with its beautifully integrated system of chromophores, electron transfer groups, and catalytic centers. Central to these photosystems are light-harvesting antennae having hundreds of precisely aligned chromophores with positions that are dictated by the proteins within the arrays. Our approach to generating similar arrangements involves the self-assembly of tobacco mosaic virus coat proteins bearing synthetic chromophore groups. These systems offer efficient light collection, are easy to prepare, and can be used to build complex photocatalytic systems through the modification of multiple sites on the protein surfaces. We then discuss protein-based carriers that can deliver drugs and imaging agents to diseased tissues. The nanoscale agents we have built for this purpose are based on the hollow protein shell of bacteriophage MS2. These 27 nm capsids have 32 pores, which allow the entry of relatively large organic molecules into the protein shell without requiring disassembly. Our group has developed a series of chemical strategies that can install dyes, radiolabels, MRI contrast agents, and anticancer drugs on the inside surface of these capsids. We have also developed methods to decorate the external surfaces with binders for specific proteins on cancer cells. As a third research area, our group has developed protein-polymer hybrid materials for water remediation. To reduce the toxicity of heavy metals in living cells, Nature has evolved metallothioneins, which are sulfur-rich polypeptides that bind mercury, cadmium, and other toxic ions at sub-parts-per-billion concentrations. Unfortunately, these proteins are very difficult to incorporate into polymers, largely because typical protein modification reactions target the very cysteine, lysine, and carboxylate-containing residues that are required for their proper function. To address this challenge, we developed a new way to attach these (and many other) proteins to polymer chains by expressing them as part of an N- and C-terminal modification "cassette". The resulting materials retain their selectivity and can remove trace amounts of toxic metal ions from ocean water. Each of these examples has presented a new set of protein bioconjugation challenges that have been met through the development of new reaction methodology. Future progress in the generation of protein-based materials will require scalable synthetic techniques with improved yields and selectivities, inexpensive purification methods for bioconjugates, and theoretical and dynamical treatments for designing new materials through protein self-assembly.     

Marketing vegetable proteins— The need for a technical understanding of these new food ingredients

The future marketing of soy products is a challenging task. Agricultural research and production have primed the pump. A process and produce development effort has maintained the pressure. Food legislators are urgently trying to find formulae for accommodating this “Novel Food.” Never before have legislators worked so closely with an evolving technology at such an early phase in the deliberations. It is essential that the delivery should do justice to the skills that have fed it. Soy producers must accept responsibility as an integral part of the food industry. The manufacturing food industry has become highly sophisticated and cost conscious, creating requirements for a wide range of food functionalities we can provide. Assignment of a new food ingredient can only be made with a thorough insight into application; its cost structure, its process machinery, its quality parameters, its nutritional significance, etc. Without this, either the wrong choice will be made, or equally dangerous, the wrong claims will be made for the correct choice. The consequent disappointment would at best delay the acceptance of what the soy food ingredient industry is trying to do. Only a commitment to understanding the food industry will allow us to define these requirements correctly and establish for our products a rightful position which we can maintain.     

涂装工程建设的新模式——COS体系

COS体系是一种集涂装、经营和服务于一体的涂装工程建设新模式,它把涂料生产厂家只卖涂料的观念转化成向客户提供优质涂膜的理念,是涂料涂装一体化的具体体现.讨论了COS体系的优点,并分享了涂料生产厂家和涂装设备厂成功应用COS体系经营的案例.     

新型绿色环保建筑材料对建筑工程造价管理影响

在社会经济高速腾飞中,建筑行业得到了迅速发展,越来越多先进的建筑材料、施工技术都涌现出来,为提高建筑施工质量做出巨大贡献.尤其是新型绿色环保建筑材料的使用,对建筑工程造价管理造成一定的影响,必须做出相应的调整.本文首先介绍新型绿色环保建筑材料优势,然后分析新型绿色环保建筑材料对工程造价管理的影响,最后提出相应的应对策略...