The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Joachim Thiem - One of the best experts on this subject based on the ideXlab platform.
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Multienzyme System for Synthesis of the Sialylated Thomsen–Friedenreich Antigen Determinant
European Journal of Organic Chemistry, 1999Co-Authors: Ulrike Gambert, Joachim ThiemAbstract:A combined sequential use of β-galactosidase from bovine testes together with α2–3-sialyltransferase from porcine liver including cofactor regeneration transforms GalNAcα1–OThr by a multistep one-pot reaction into the sialylated Thomsen–Friedenreich antigen determinant Neu5Acα2–3Galβ1–3GalNAcα1-OThr.
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Multienzyme System for synthesis of the sialylated thomsen friedenreich antigen determinant
European Journal of Organic Chemistry, 1999Co-Authors: Ulrike Gambert, Joachim ThiemAbstract:A combined sequential use of β-galactosidase from bovine testes together with α2–3-sialyltransferase from porcine liver including cofactor regeneration transforms GalNAcα1–OThr by a multistep one-pot reaction into the sialylated Thomsen–Friedenreich antigen determinant Neu5Acα2–3Galβ1–3GalNAcα1-OThr.
Joachim Vater - One of the best experts on this subject based on the ideXlab platform.
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purification of the fengycin synthetase Multienzyme System from bacillus subtilis b213
Journal of Chromatography B: Biomedical Sciences and Applications, 2000Co-Authors: Sigrid Steller, Joachim VaterAbstract:Abstract The purification of the Multienzyme System producing the lipodecapeptide fengycin in Bacillus subtilis b213 was investigated. By gel filtration of a cell free extract of this organism three enzyme fractions were obtained from which five multifunctional components of fengycin synthetase were separated by high resolution anion-exchange FPLC procedures. These proteins were characterized by their thioester formation activities with 14 C-labeled substrate amino acids and by N-terminal sequencing. Correlation of these data with the DNA sequences of the pps (fen) operons in three B. subtilis strains provided detailed knowledge on the structural and functional organization of fengycin synthetase.
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structural and functional organization of the fengycin synthetase Multienzyme System from bacillus subtilis b213 and a1 3
Chemistry & Biology, 1999Co-Authors: Sigrid Steller, Dirk Vollenbroich, Frank Leenders, Torsten Stein, Birgit Conrad, Jurgen Hofemeister, Philippe Jacques, Philippe Thonart, Joachim VaterAbstract:Background Bacillus subtilis strains produce a broad spectrum of lipopeptides that are potent biosurfactants and have specific antimicrobial and antiviral activities. The cyclic lipodecapeptide fengycin is one such compound. Although the fengycin biosynthetic genes in B. subtilis 168 ( pps genes) and F29-3 ( fen genes) have been well characterized, only limited information is available about the biochemical features of the fengycin synthetase Multienzyme System. Results Five multifunctional peptide synthetases (Fen 1–5) that catalyze biosynthesis of the peptide portion of fengycin have been purified from crude extracts of the B. subtilis b213 and A1/3 strains. These enzymes activate all fengycin amino-acid components as aminoacyl adenylates or aminoacyl thioesters. Fen1, Fen2 and Fen3 are each ~286 kDa, Fen4 is ~400 kDa and Fen 5 is ~140kDa; each enzyme activates a different set of l-amino acids. A five-gene cluster ( fen 1–5) was detected in the B. subtilis A1/3 genome that shows high homology to the pps and fen genes in B. subtilis strains 168 and F29-3. Disruption of fen4 resulted in a loss of fengycin production. The fengycin synthetase enzymes isolated from B. subtilis b213 were assigned to the corresponding A1/3 fen genes by their amino-terminal sequences. Conclusions The structural and functional organization of the fengycin synthetase System from B. subtilis b213 has been characterized in detail and correlated with the corresponding pps and fen genes in B. subtilis strains 168, A1/3 and F29-3. Biosynthesis of the peptide part of fengycin involves five multifunctional modular proteins that assemble the lipopeptide chain using a nonribosomal, multiple carrier thiotemplate mechanism.
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structural and functional organization of the surfactin synthetase Multienzyme System
Journal of Biological Chemistry, 1993Co-Authors: M Menkhaus, C Ullrich, Britta Kluge, Joachim Vater, Dirk Vollenbroich, Roza Maria KampAbstract:Abstract By gel filtration of a crude extract of Bacillus subtilis ATCC 21332 and OKB 105, the Multienzyme System that forms the lipoheptapeptide surfactin was separated into three enzyme fractions, E1, E2, and E3. E1, which appeared near the exclusion limit of the column, activates all amino acid components of surfactin as aminoacyladenylates and thioesters according to the thioester mechanism. In addition, a leucine-activating enzyme (E2) and an acyltransferase (E3) were detected that show molecular masses of approximately 160 and 40 kDa, respectively. The surfactin synthetase Multienzyme System was reconstituted by complementation of all three enzyme fractions, yielding high rates of lipopeptide formation. E1 is composed of two multifunctional polypeptides (E1A and E1B) with molecular masses of 460 and 435 kDa, respectively, that can be separated by high-resolution anion-exchange chromatography on Pharmacia Mono Q. E1A binds L-Glu and L-Leu in a molar ratio of 1:2, whereas E1B incorporates L-Val, L-Asp, and L-Leu in a molar ratio of 1:1:1. The hydroxy fatty acid moiety is contributed by the acyltransferase accepting the hydroxy fatty acid coenzyme A thioester as substrate. The transfer of the hydroxy fatty acid to E1A and the formation of the hydroxyacyl-L-glutamate intermediate are the initiation steps in the biosynthesis of surfactin. The amino acid-activating enzyme components E1A, E1B, and E2 have been highly purified and partially characterized.
Lei Zhang - One of the best experts on this subject based on the ideXlab platform.
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Bioinspired preparation of polydopamine microcapsule for Multienzyme System construction
Green Chemistry, 2020Co-Authors: Lei Zhang, Ruijie Meng, Shizhang Qiao, Yanjun Jiang, Zhongyi Jiang, Rui Wang, Jian Li, Yang ZhengAbstract:Inspired by the structural organization of mitochondria and the bioadhesive principle, a simple and versatile approach to construct a Multienzyme System is developed. More specifically, the Multienzyme System is composed of a polydopamine (PDA) microcapsule scaffold and three spatially separated enzymes. The PDA microcapsules are prepared through the rapid, spontaneous self-polymerization of dopamine on the surface of CaCO3 microparticle template, followed by dissolution of the template using EDTA. The wall thickness of the microcapsules can be tuned by the dopamine concentration in an aqueous solution. The three enzymes are respectively immobilized through physical encapsulation in the lumen, in situ entrapment within the wall and chemical attachment on the out surface under extremely mild conditions. As an example, a Multienzyme System, containing α-amylase, β-amylase and glucosidase, was constructed to convert starch into isomaltooligosaccharide, and the Multienzyme System displays higher catalytic activity and enhanced operational stability. The method developed in this study will establish a powerful platform for the facile construction of Multienzyme cascade Systems.
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facile construction of multicompartment Multienzyme System through layer by layer self assembly and biomimetic mineralization
ACS Applied Materials & Interfaces, 2011Co-Authors: Lei Zhang, Zhongyi JiangAbstract:In nature, some organelles such as mitochondria and chloroplasts possess multicompartment structure, which render powerful and versatile performance in cascade conversion, selective separation, and energy transfer. In this study, mitochondria-inspired hybrid double membrane microcapsules (HDMMCs) were prepared through synergy between biomimetic mineralization and layer-by-layer (LbL) self-assembly using double templating strategy. The organic inner membrane was acquired via LbL self-assembly of oxidized alginate (o-alginate) and protamine on the CaCO3 template, the silica template layer was then formed onto the inner membrane through biomimetic silicification using protamine as inducer and silicate as precursor, the organic−inorganic hybrid outer membrane was acquired via biomimetic mineralization of titanium precursor. After the CaCO3 template and the silica template are removed subsequently, multicompartment microcapsules with microscale lumen and nanoscale intermembrane space were obtained. The double ...
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Bioinspired preparation of polydopamine microcapsule for Multienzyme System construction
Green Chemistry, 2011Co-Authors: Lei Zhang, Ruijie Meng, Jiafu Shi, Yuanyuan Zhu, Shizhang Qiao, Yanjun Jiang, Zhongyi Jiang, Rui Wang, Jian Li, Yang ZhengAbstract:Inspired by the structural organization of mitochondria and the bioadhesive principle, a simple and versatile approach to construct a Multienzyme System is developed. More specifically, the Multienzyme System is composed of a polydopamine (PDA) microcapsule scaffold and three spatially separated enzymes. The PDA microcapsules are prepared through the rapid, spontaneous self-polymerization of dopamine on the surface of CaCO(3) microparticle template, followed by dissolution of the template using EDTA. The wall thickness of the microcapsules can be tuned by the dopamine concentration in an aqueous solution. The three enzymes are respectively immobilized through physical encapsulation in the lumen, in situ entrapment within the wall and chemical attachment on the out surface under extremely mild conditions. As an example, a Multienzyme System, containing alpha-amylase, beta-amylase and glucosidase, was constructed to convert starch into isomaltooligosaccharide, and the Multienzyme System displays higher catalytic activity and enhanced operational stability. The method developed in this study will establish a powerful platform for the facile construction of Multienzyme cascade Systems.
Ulrike Gambert - One of the best experts on this subject based on the ideXlab platform.
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Multienzyme System for Synthesis of the Sialylated Thomsen–Friedenreich Antigen Determinant
European Journal of Organic Chemistry, 1999Co-Authors: Ulrike Gambert, Joachim ThiemAbstract:A combined sequential use of β-galactosidase from bovine testes together with α2–3-sialyltransferase from porcine liver including cofactor regeneration transforms GalNAcα1–OThr by a multistep one-pot reaction into the sialylated Thomsen–Friedenreich antigen determinant Neu5Acα2–3Galβ1–3GalNAcα1-OThr.
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Multienzyme System for synthesis of the sialylated thomsen friedenreich antigen determinant
European Journal of Organic Chemistry, 1999Co-Authors: Ulrike Gambert, Joachim ThiemAbstract:A combined sequential use of β-galactosidase from bovine testes together with α2–3-sialyltransferase from porcine liver including cofactor regeneration transforms GalNAcα1–OThr by a multistep one-pot reaction into the sialylated Thomsen–Friedenreich antigen determinant Neu5Acα2–3Galβ1–3GalNAcα1-OThr.
Zhongyi Jiang - One of the best experts on this subject based on the ideXlab platform.
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Bioinspired preparation of polydopamine microcapsule for Multienzyme System construction
Green Chemistry, 2020Co-Authors: Lei Zhang, Ruijie Meng, Shizhang Qiao, Yanjun Jiang, Zhongyi Jiang, Rui Wang, Jian Li, Yang ZhengAbstract:Inspired by the structural organization of mitochondria and the bioadhesive principle, a simple and versatile approach to construct a Multienzyme System is developed. More specifically, the Multienzyme System is composed of a polydopamine (PDA) microcapsule scaffold and three spatially separated enzymes. The PDA microcapsules are prepared through the rapid, spontaneous self-polymerization of dopamine on the surface of CaCO3 microparticle template, followed by dissolution of the template using EDTA. The wall thickness of the microcapsules can be tuned by the dopamine concentration in an aqueous solution. The three enzymes are respectively immobilized through physical encapsulation in the lumen, in situ entrapment within the wall and chemical attachment on the out surface under extremely mild conditions. As an example, a Multienzyme System, containing α-amylase, β-amylase and glucosidase, was constructed to convert starch into isomaltooligosaccharide, and the Multienzyme System displays higher catalytic activity and enhanced operational stability. The method developed in this study will establish a powerful platform for the facile construction of Multienzyme cascade Systems.
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bioinspired approach to Multienzyme cascade System construction for efficient carbon dioxide reduction
ACS Catalysis, 2014Co-Authors: Xiaoli Wang, Zhongyi Jiang, Zheng Li, Hong Wu, Wenyan Zhang, Xiaokai Song, Qinghong AiAbstract:An efficient Multienzyme cascade System based on ultrathin, hybrid microcapsules was constructed for converting CO2 to methanol by combining the unique functions of catechol and gelatin. Gelatin was modified with catechol groups (GelC) via well-defined EDC/NHS chemistry, thus endowed with the ability to covalently attach enzyme molecules. Next, the first enzyme (FateDH)-containing CaCO3 templates were synthesized via coprecipitation and coated with a GelC layer. Afterward, GelC was covalently attached with the second enzyme (FaldDH) via Michael addition and Schiff base reactions. Then, GelC induced the hydrolysis and condensation of silicate, and the third enzyme (YADH) was entrapped accompanying the formation of silica particles. After removal of CaCO3 templates, the GelCSi-based Multienzyme System was obtained, in which the three enzymes were appropriately positioned in different places of the GelCSi microcapsules, and the amount of individual enzyme was regulated according to enzyme activity. The syste...
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constructing spatially separated Multienzyme System through bioadhesion assisted bio inspired mineralization for efficient carbon dioxide conversion
Bioresource Technology, 2012Co-Authors: Xiaoli Wang, Zhongyi Jiang, Yanpeng Liang, Chunhong ZhangAbstract:Abstract A facile and green bioadhesion-assisted bio-inspired mineralization ( BABM ) approach is proposed to construct spatially separated Multienzyme System for conversion of carbon dioxide to formaldehyde. Specifically, formate dehydrogenase is entrapped accompanying the formation of titania nanoparticles (NPs) through bio-inspired titanification. After in situ surface functionalization of NPs with oligodopa, formaldehyde dehydrogenase is immobilized on the surface of NPs through amine-catechol adduct reaction. Compared to co-immobilized and free Multienzyme System, the spatially separated Multienzyme System exhibits significantly enhanced formaldehyde yield, selectivity and initial specific activity. The influence of particle size on the enzyme activity reveals that the formaldehyde yield (80.9%, 52.9%, 46.4%), selectivity (92.7%, 86.6%, 85.1%) and initial specific activity (1.87, 1.31, 0.29 U mg −1 ) all decreased as the NPs particle size increased from 75, 175 to 375 nm. After storing for 20 days at 4 °C, this Multienzyme System retains as high as 70% of its initial activity.
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facile construction of multicompartment Multienzyme System through layer by layer self assembly and biomimetic mineralization
ACS Applied Materials & Interfaces, 2011Co-Authors: Lei Zhang, Zhongyi JiangAbstract:In nature, some organelles such as mitochondria and chloroplasts possess multicompartment structure, which render powerful and versatile performance in cascade conversion, selective separation, and energy transfer. In this study, mitochondria-inspired hybrid double membrane microcapsules (HDMMCs) were prepared through synergy between biomimetic mineralization and layer-by-layer (LbL) self-assembly using double templating strategy. The organic inner membrane was acquired via LbL self-assembly of oxidized alginate (o-alginate) and protamine on the CaCO3 template, the silica template layer was then formed onto the inner membrane through biomimetic silicification using protamine as inducer and silicate as precursor, the organic−inorganic hybrid outer membrane was acquired via biomimetic mineralization of titanium precursor. After the CaCO3 template and the silica template are removed subsequently, multicompartment microcapsules with microscale lumen and nanoscale intermembrane space were obtained. The double ...
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Bioinspired preparation of polydopamine microcapsule for Multienzyme System construction
Green Chemistry, 2011Co-Authors: Lei Zhang, Ruijie Meng, Jiafu Shi, Yuanyuan Zhu, Shizhang Qiao, Yanjun Jiang, Zhongyi Jiang, Rui Wang, Jian Li, Yang ZhengAbstract:Inspired by the structural organization of mitochondria and the bioadhesive principle, a simple and versatile approach to construct a Multienzyme System is developed. More specifically, the Multienzyme System is composed of a polydopamine (PDA) microcapsule scaffold and three spatially separated enzymes. The PDA microcapsules are prepared through the rapid, spontaneous self-polymerization of dopamine on the surface of CaCO(3) microparticle template, followed by dissolution of the template using EDTA. The wall thickness of the microcapsules can be tuned by the dopamine concentration in an aqueous solution. The three enzymes are respectively immobilized through physical encapsulation in the lumen, in situ entrapment within the wall and chemical attachment on the out surface under extremely mild conditions. As an example, a Multienzyme System, containing alpha-amylase, beta-amylase and glucosidase, was constructed to convert starch into isomaltooligosaccharide, and the Multienzyme System displays higher catalytic activity and enhanced operational stability. The method developed in this study will establish a powerful platform for the facile construction of Multienzyme cascade Systems.