Oleate Hydratase from Lactobacillus rhamnosus ATCC 53103: A FADH2-Dependent Enzyme with Remarkable Industrial Potential

Recently, we described the preparation of the recombinant oleate hydratase from Lactobacillus rhamnosus ATCC 53103. We observed that the purified C-terminal His-tagged enzyme was completely inactive and the catalytic activity was partially restored only in presence of a large amount of flavin adenine dinucleotide (FAD). In the present work, we assess that this hydratase in the presence of the reduced form of flavin adenine dinucleotide (FADH2) is at least one hundred times as active as in the presence of the same concentration of FAD. By means of two different biochemical processes, we demonstrated unambiguously that oleate hydratase from Lactobacillus rhamnosus ATCC 53103 is a FADH2-dependent enzyme. As a first relevant application of this discovery, we devised a preparative procedure for the stereoselective synthesis of (R)-10-hydroxystearic acid. Accordingly, the hydration of oleic acid (up to 50 g/L) is performed on a multigram scale using the recombinant hydratase and FADH2 generated in situ as cofactor. The produced (R)-10-hydroxystearic acid (ee > 97%) precipitates from the reaction solvent (water/glycerol/ethanol) and is conveniently recovered by simple filtration (>90% yield).

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3-D imaging of cells using a confocal laser scanning microscope and digital image processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102560 ◽

1988 ◽

Vol 46 ◽

pp. 96-97

Author(s):

Thomas M. Jovin ◽

Michel Robert-Nicoud ◽

Donna J. Arndt-Jovin ◽

Thorsten Schormann

Keyword(s):

Laser Scanning ◽

Confocal Laser Scanning Microscope ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Confocal Laser ◽

Scanning Microscope ◽

Laser Scanning Microscope ◽

Biochemical Processes ◽

Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

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ChemInform Abstract: Highly Stereoselective Synthesis of Saccharin-Substituted β-Lactams via in situ Generation of a Heterosubstituted Ketene and a Zwitterionic Intermediate as Potential Antibacterial Agents.

ChemInform ◽

10.1002/chin.201543112 ◽

2015 ◽

Vol 46 (43) ◽

pp. no-no

Author(s):

Zahra F. A. Mortazavi ◽

Mohammad R. Islami ◽

Moj Khaleghi

Keyword(s):

Antibacterial Agents ◽

Stereoselective Synthesis ◽

In Situ Generation ◽

Zwitterionic Intermediate

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Fabrication of cellulosic paper containing zeolitic imidazolate framework and its application in removal of anionic dye from aqueous solution

BioResources ◽

10.15376/biores.16.2.2644-2654 ◽

2021 ◽

Vol 16 (2) ◽

pp. 2644-2654

Author(s):

Zicheng Chen ◽

Huiwen Zhang ◽

Xiangyang He ◽

Guangyuan Fan ◽

Xiaosong Li ◽

...

Keyword(s):

Aqueous Solution ◽

Functional Materials ◽

Anionic Dyes ◽

Zeolitic Imidazolate Framework ◽

Cellulosic Fibers ◽

Simple Filtration ◽

Metal Organic ◽

Potential Strategy ◽

Cellulosic Paper

The combination of metal organic frameworks (MOFs) with other functional materials is a potential strategy for the preparation of advanced MOF-based materials. In this study, a simple approach is reported for the fabrication of cellulosic paper containing zeolitic imidazolate framework (ZIF-8) through in-situ loading in the papermaking process. The results showed that the ZIF-8 was evenly distributed in the paper substrate owing to the multi-layers structure of the cellulosic fibers, although the loading of the ZIF-8 particles on the single cellulosic fiber was nonuniform. The as-prepared ZIF-8 composites can be used as a highly efficient adsorbent material for anionic dyes in aqueous solution thanks to the positive charge on the surface of the ZIF-8 particles. More than 92% of the methyl orange (MO-) dye in the aqueous solution was rapidly removed through a simple filtration process using the ZIF-8 composite cellulosic paper (hand-sheets made in lab) when the content of ZIF-8 in cellulosic paper was high as 25.1%. In addition, the ZIF-8 composite paper had acceptable flexibility and could be reused at least 4 cycles by washing out the adsorbed dye.

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A Metal-free and β-Stereoselective Synthesis of 2-Deoxy-C-aryl Glycosides: Synthesis of 5-aza analogues of Aquayamycin

Synlett ◽

10.1055/a-1670-2290 ◽

2021 ◽

Author(s):

Yuling Mei ◽

nan jiang ◽

Yu Yang ◽

Wan Zhang ◽

Saifeng Qiu ◽

...

Keyword(s):

Stereoselective Synthesis ◽

Metal Free ◽

Wide Range ◽

One Step ◽

Aryl Glycosides ◽

Aryl Glycoside

A convenient protocol for β-stereoselective synthesis of 2-deoxy-C-aryl glycosides has been developed. This reaction takes place in one step by using I2/Et3SiH to activate glycosyl acetate to generate glycosyl iodide intermediate in situ, which was captured by naphthol followed by Fries-like O- → C-glycoside rearrangement to selectively afford β-C-aryl glycoside. The approach is applicable to a wide range of naphthol modules, and its utility was demonstrated in the synthesis of 5-aza analogues of Aquayamycin.

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Supramolecular Control of Photocycloadditions in Solution: In Situ Stereoselective Synthesis and Release of Cyclobutanes

Angewandte Chemie ◽

10.1002/ange.201900221 ◽

2019 ◽

Vol 131 (12) ◽

pp. 4026-4031 ◽

Cited By ~ 9

Author(s):

Li‐Li Ma ◽

Yuan‐Yuan An ◽

Li‐Ying Sun ◽

Yao‐Yu Wang ◽

F. Ekkehardt Hahn ◽

...

Keyword(s):

Stereoselective Synthesis ◽

Supramolecular Control

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Ru-catalyzed isomerization of ω-alkenylboronates towards stereoselective synthesis of vinylboronates with subsequent in situ functionalization

Chemical Science ◽

10.1039/d0sc02542a ◽

2020 ◽

Vol 11 (23) ◽

pp. 5944-5949 ◽

Cited By ~ 4

Author(s):

Guo-Ming Ho ◽

Lucas Segura ◽

Ilan Marek

Keyword(s):

Stereoselective Synthesis ◽

In Situ Functionalization

A regio- and stereoselective ruthenium-catalyzed isomerization of ω-alkenyl boronates into stereodefined di- and trisubstituted alkenylboronate derivatives is reported.

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