Directed evolution of new catalytic activity using the alpha/beta-barrel scaffold

In biological systems, enzymes catalyse the efficient synthesis of complex molecules under benign conditions, but widespread industrial use of these biocatalysts depends crucially on the development of new enzymes with useful catalytic functions. The evolution of enzymes in biological systems often involves the acquisition of new catalytic or binding properties by an existing protein scaffold. Here we mimic this strategy using the most common fold in enzymes, the alpha/beta-barrel, as the scaffold. By combining an existing binding site for structural elements of phosphoribosylanthranilate with a catalytic template required for isomerase activity, we are able to evolve phosphoribosylanthranilate isomerase activity from the scaffold of indole-3-glycerol-phosphate synthase. We find that targeting the catalytic template for in vitro mutagenesis and recombination, followed by in vivo selection, results in a new phosphoribosylanthranilate isomerase that has catalytic properties similar to those of the natural enzyme, with an even higher specificity constant. Our demonstration of divergent evolution and the widespread occurrence of the alpha/beta-barrel suggest that this scaffold may be a fold of choice for the directed evolution of new biocatalysts.     

生物催化绿色制造精细化学品进展与实例

生物催化是精细化工增效减排的重要手段.基因组数据库和DNA合成技术的发展降低了生物催化酶的开发成本,使得近年来生物催化应用大大提速.以中科院上海生命科学院参与的相关项目为主,综述了国内近十多年来的生物催化在精细化工领域的应用实例,并讨论了生物催化面临的机遇与挑战.     

壬二酸的性质、合成和应用

本综述了壬二酸的性质，用途及合成方法。介绍了国内外采用臭氧氧化法合成壬二酸的研究进展。对臭氧氧化法合成壬二酸的反应机理，合成工艺做了较为系统的总结并对臭氧氧化法在精细化工中的应用做了展望：臭氧氧化法作为一种清洁工艺在油脂深加工和精细化工产品的开发方面大有可为。     

离子液体中氮杂环化合物的合成研究进展

离子液体是一类性能优异、用途广泛的溶剂,在诸多领域具有独特的性质,已经在有机合成领域得到广泛的应用。总结了近年来离子液体在氮杂环化合物合成中的研究进展。     

5株植物内生真菌生物转化柠檬烯和月桂烯产物分析

为了筛选具有转化利用单萜类化合物能力的微生物菌株,以5株植物内生真菌为生物催化剂,(+)-柠檬烯、(-)-柠檬烯、月桂烯为生物转化底物,结合气相色谱-质谱联用技术考察生物转化产物.结果表明：5株植物内生真菌具有生物转化(+)-柠檬烯、(-)-柠檬烯、月桂烯的能力;当底物为(+)-柠檬烯时,主要产物均为柠檬烯-1,2-二醇,其中,菌株Diaporthe Nitschke PS10的产量最高,达到4.57 g·L^-1;当底物为(-)-柠檬烯时,主要产物为柠檬烯-1,2-二醇,产量为0.81～2.04 g·L^-1;当底物为月桂烯时,转化产物有环氧罗勒烯、氧化芳樟醇、柠檬烯-1,2-二醇等化合物;植物内生真菌是一种很有发展潜力的生物催化剂.     

Laboratory evolution of peroxide-mediated cytochrome P450 hydroxylation.

Enzyme-based chemical transformations typically proceed with high selectivity under mild conditions, and are becoming increasingly important in the pharmaceutical and chemical industries. Cytochrome P450 monooxygenases (P450s) constitute a large family of enzymes of particular interest in this regard. Their biological functions, such as detoxification of xenobiotics and steroidogenesis, are based on the ability to catalyse the insertion of oxygen into a wide variety of compounds. Such a catalytic transformation might find technological applications in areas ranging from gene therapy and environmental remediation to the selective synthesis of pharmaceuticals and chemicals. But relatively low turnover rates (particularly towards non-natural substrates), low stability and the need for electron-donating cofactors prohibit the practical use of P450s as isolated enzymes. Here we report the directed evolution of the P450 from Pseudomonas putida to create mutants that hydroxylate naphthalene in the absence of cofactors through the 'peroxide shunt' pathway with more than 20-fold higher activity than the native enzyme. We are able to screen efficiently for improved mutants by coexpressing them with horseradish peroxidase, which converts the products of the P450 reaction into fluorescent compounds amenable to digital imaging screening. This system should allow us to select and develop mono- and di-oxygenases into practically useful biocatalysts for the hydroxylation of a wide range of aromatic compounds.     

鸢尾黄素的研究进展

鸢尾黄素是一种天然存在的异黄酮,本文从生物活性和合成两大方面对鸢尾黄素的研究状况进行了综述。     

甜菜碱的生物合成及其基因工程的研究进展

综述了甜菜碱的合成过程和催化酶类的相关特性。并对催化甜菜碱合成的胆碱脱氢酶(CDH)、胆碱单加氧酶(CMO)、甜菜碱醛脱氢酶(BADH)、胆碱氧化酶(COD)基因工程方面的研究进展进行了综述．     

Privileged chiral catalysts in asymmetric Morita-Baylis-Hillman/aza-Morita-Baylis-Hillman reaction

In the past decade, the asymmetric Morita-Baylis-Hillman (MBH)/aza-Morita-Baylis-Hillman (aza-MBH) reaction has attracted great attention because it leads to the formation of densely functionalized products in a catalytic and atom-economic way. The MBH/aza-MBH adducts can be further applied in a wide variety of organic synthesis, such as peptide synthesis and heterocyclic compounds synthesis. After a lot of attempts to improve the enantioselectivity, many types of chiral organocatalysts have been identified as highly enantioselective organocatalysts in MBH/aza-MBH reaction. Especially, certain “privileged chiral catalysts” are highly enantioselective in MBH/aza-MBH reaction, which are designed and developed through introducing bi-/multi-functional groups on the so-called “privileged structures” such as cinchona alkaloids, BINAP/BINOL. This review summarizes the exciting advances about the design and development of chiral catalysts derived from “privileged structures” and their applications in asymmetric MBH/aza-MBH reaction.     

1 ,1’ -联二萘酚化合物的合成研究进展

综述了近年来 1,1’ -联二萘酚类化合物合成研究进展 ,引用文献 5 1篇     

脂肪酶在生物化工中的应用

脂肪酶是一种具有广泛应用潜力的生物催化剂 .本文详细地介绍了脂肪酶在生物化工各个领域中的应用情况 .     

Aza—Wittig反应最新进展

综述了最近１０年来ａｚａ－Ｗｉｔｔｉｇ反应在氮杂环合成中的应用．     

过渡金属/磷配体络合物催化不对称氢甲酰化研究进展

手性醛是合成生物活性物质如药物活性分子等的重要中间体,及各种高附加值精细化学品如香料等的起始原料,潜手性烯烃及其衍生物的不对称氢甲酰化是合成光学活性醛的重要方法之一.在烯烃的不对称氢甲酰化中铑与膦形成的催化体系因活性高、选择性好等优点而被广泛应用.主要介绍了近年来几类新型手性磷配体与铑形成的络合物催化剂在不对称氢甲酰化反应中的应用研究结果,如Rh/手性双-3,4-二氮磷杂环戊烷配体(S,S,S)-Bisdiazaphos和(R,S)-NEt-Yanpho络合物催化剂等.     

糖基转移酶合成相关糖苷类化合物研究进展

许多天然产物是中药中的活性成份,拥有良好的药理活性。通过糖基化反应后形成的糖苷类化合物可以提高天然产物的稳定性、水溶性和生物利用度,因而受到越来越多的关注。糖苷类化合物一般通过化学合成和植物提取的方式获得,近年来利用糖基转移酶合成糖苷类化合物成为了一个研究热点。糖基转移酶是通过天然产物合成糖苷类化合物的关键酶,作为一类庞大的基因家族酶,通常来源于植物和微生物。本文将阐述利用糖基转移酶合成糖苷类化合物的研究进展,为糖基转移酶合成糖苷类化合物工业化提供参考和方向。     

非水相体系中的脂肪酶催化反应制备酯化葡甘聚糖的初步研究

研究了在各种非水相反应体系中以不同的脂肪酶为催化剂的魔芋葡甘聚糖(KGM)的酶催化酯化和转酯化反应,以探索制备酯化KGM衍生物的可行的、环境友好的新途径.初步的实验结果表明通过非水相反应体系中的脂肪酶催化反应能够制得KGM的酯化衍生物;在适宜的条件下,脂肪酶Lipase-OF和Lipozyme Tl 100L 是制备酯化KGM的有效的生物催化剂.     

Phytochromes and light signal perception by plants--an emerging synthesis

For plants, the sensing of light in the environment is as important as vision is for animals. Fluctuations in light can be crucial to competition and survival. One way plants sense light is through the phytochromes, a small family of diverse photochromic protein photoreceptors whose origins have been traced to the photosynthetic prokaryotes. During their evolution, the phytochromes have acquired sophisticated mechanisms to monitor light. Recent advances in understanding the molecular mechanisms of phytochromes and their significance to evolutionary biology make possible an interim synthesis of this rapidly advancing branch of photobiology.     

均三甲苯的生产技术研究

本文介绍了均三甲苯生产技术研究的最新进展，其中包括合成法、分离提纯法和反应－分离复合法等均三甲苯生产技术。     

毒隐翅虫研究进展：2.毒素及其在医学上的重要意义

本文对毒隐翅虫毒素的分析、合成、生化特性,在虫体内的出处,毒理学与病理学,药理学,在癌及细胞生物学上的意义作了综述.     

桥联和取代环戊二烯基稀土金属有机化学进展

介绍了取代环戊二烯和桥联双环戊二烯基稀土金属有机化学的进展，包括稀土金属有机配合物的合成，结构和反性能的研究。     

Synthesis and medical applications of oligosaccharides

Our understanding of the different glycoconjugates present on cells, proteins and entire organisms is lagging far behind advances in genomics and proteomics. Carbohydrate sequencing and the synthesis of defined oligosaccharides are two key technologies that have contributed to progress in glycomics research. Synthetic tools and high-throughput experiments such as carbohydrate arrays are beginning to affect biological research. These techniques are now being applied to the development of carbohydrate-based diagnostics, vaccines and therapeutics.