Chemo- and Regioselective Monosulfonylation of Nonprotected Carbohydrates Catalyzed by Organotin Dichloride under Mild Conditions
摘要:
The catalytic regioselective monosulfonylation of nonprotected carbohydrates using organotin dichloride under mild conditions is examined. The carbohydrates were chemo- and regioselectively converted to the corresponding monosulfonates in the presence of monoalcohols using catalytic dibutyltin dichloride. The regioselectivity of the sulfonylation is attributed to the intrinsic character of the carbohydrates derived from the relative stereochemistry between their hydroxy groups.
Biosynthesis of indigo in Escherichia coli expressing self-sufficient CYP102A from Streptomyces cattleya
摘要:
Cytochrome P450 monooxygenases (CYP) are a superfamily of heme-thiolate proteins which catalyze the incorporation of oxygen atoms into substrates. Here, a self-sufficient CYP102A from Streptomyces cattleya (CYP102A_scat) was cloned, produced recombinantly in Escherichia coli strain BL21 (DE3), and the characteristic features were investigated. However, unlike other self-sufficient CYP102A enzymes that have been reported, CYP102A_scat was found to be able to catalyze intracellular hydroxylation of indole molecules with 3-C specific regioselectivity. Consequently, E. coli strains producing CYP102A_scat could synthesize approximately 1.0 g/L of indigo in LB media. Optimization of indigo synthesis was investigated through additional feeding of indole precursors such as glucose, L-tryptophan, and indole. Indigo production reached up to 3.8 +/- 0.1 g/L by adding 20 mu M of extracellular indole and 0.2 mM of L-tryptophan to the LB media. To our knowledge, this is a record and the highest yield achieved so far. 2017 Elsevier Ltd. All rights reserved.
Glycoconjugate and sugar nucleotide synthesis using solid supports
申请人:——
公开号:US20020150968A1
公开(公告)日:2002-10-17
This invention relates to methods and compositions for the in vitro production of glycoconjugates. In particular, a preferred production system is provided that comprises a solid support, at least one sugar nucleotide producing enzyme, at least one glycosyltransferase, at least one bioenergetic, and at least one acceptor. The sugar nucleotide producing enzyme(s) is preferably immobilized on the solid support. The glycosyltransferase may be co-immobilized on the solid support with the sugar nucleotide producing enzyme(s), or may be provided to the solid support in solution.
A vaccine for the immunization of a vertebrate comprising a non-pathogenic microbe that expresses a recombinant gene derived from an organism that is a pathogen of, or that produces an allergen of, said animal, where the gene codes for a gene product that is an antigen capable of being recognized by the immune system of the vertebrate and inducing antibody formation against the pathogen or allergen. '
The use of microbes of the nature described above to produce non-living vaccines comprising such gene products essentially in the absence of other antigenic material from the parent organism.
The cloning and expression of nucleotide sequences encoding bovine growth hormone
申请人:MGI PHARMA, INC.
公开号:EP0111814A2
公开(公告)日:1984-06-27
Methods and compositions are provided for the cloning and expression of bovine growth hormone (BGH) genetic sequences in single-cell host organisms. Also described are methods for culturing these novel single cell organisms to produce polypeptides having growth hormone activity and methods for purification of the gene product. Recombinant plasmids were constructed so as to provide an "optimal" system for the expression of BGH gene sequences in compatible host cells. The BGH related proteins produced by the recombinant DNA techniques described herein may be used in animal husbandry and in veterinary medicine.
Immunologically reactive non-glycosylated amino acid chains of glycoprotein B of herpes virus types 1 and 2
申请人:Person, Stanley, Dr.
公开号:EP0133063A1
公开(公告)日:1985-02-13
Plasmids are constructed containing the nucleotide sequence for selectively expressing immunologically active amino acid chains of glycoprotein B of HSV-1 and HSV-2 and chains are prepared to serve in vaccines.
构建的质粒含有选择性表达 HSV-1 和 HSV-2 糖蛋白 B 的免疫活性氨基酸链的核苷酸序列,并制备了用于疫苗的氨基酸链。
A xenogeneic expression control system, a method of using it, expression vectors containing it, cells transformed thereby and heterologous proteins produced therefrom
申请人:GENENTECH, INC.
公开号:EP0136907A2
公开(公告)日:1985-04-10
A portable supplementary control system comprising a promoter/operator operably linked to a gene encoding the desired heterologous protein plus a gene encoding a compatible supplementary repressor protein operably linked to an inducible promotor, thus remedying any deficiency of repressor provided by the host's own genome, so that expression of a gene encoding a heterologous protein is repressed until a favourable point in the growth cycle of the host. The control system offers a method whereby heterologous protein production can be regulated by manipulation of the environment or of the medium.