Chemo-enzymatic synthesis of Lacto-N-biose I catalyzed by β-1,3 galactosidase from Bacillus circulans using 4,6-dimethoxy-1,3,5-triazin-2-yl β-galactopyranoside as a glycosyl donor

2021 ◽  
Author(s):  
Takayuki Ohnuma ◽  
Tomoki Taku ◽  
Takeshi Nagatani ◽  
Atsushi Horii ◽  
Shun Imaoka ◽  
...  
Keyword(s):  
Enzymatic Synthesis ◽  
Maximum Yield ◽  
Bacillus Circulans ◽  
Donor Substrate ◽  
Donor And Acceptor ◽  
Glycosyl Donor ◽  
Substrate Ratio

Abstract Chemo-enzymatic synthesis of lacto-N-biose I (LNB) catalyzed by β-1,3 galactosidase from Bacillus circulans (BgaC) has been developed using 4,6-dimethoxy-1,3,5-triazin-2-yl β-galactopyranoside [DMT-β-Gal] and GlcNAc as the donor and acceptor substrates, respectively. BgaC transferred the Gal moiety to the acceptor, giving rise to LNB. The maximum yield of LNB was obtained at the acceptor: donor substrate ratio of 1:30.

scholarly journals Kinetics of Non-Enzymatic Synthesis of Dipeptide Cbz-Phe-Leu with AOT Reversed Micelles

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1003
Author(s):  
Michiaki Matsumoto ◽  
Tadashi Hano
Keyword(s):  
Enzymatic Synthesis ◽  
Maximum Yield ◽  
Side Reactions ◽  
Experimental Conditions ◽  
Operational Conditions ◽  
Ph Dependency ◽  
Optimum Water Content ◽  
Short Time ◽  
Kinetics Of ◽  
Aot Reversed Micelles

The non-enzymatic synthesis of N-benzyloxycarbonyl-L-phenylalanyl-L-leucine (Cbz-Phe-Leu) from lipophilic N-benzyloxycarbonyl-L-phenylalanine (Cbz-Phe) and hydrophilic L-leucine (Leu), by N, N’-dicyclohexylcarbodiimide (DCC) as a condensing agent, was carried out using a reversed micellar system composed of bis(2-ethylhexyl) sodium sulfosuccinate (AOT) as a surfactant and isooctane. We successfully synthesized Cbz-Phe-Leu in a short time and investigated the effects of its operational conditions, the DCC concentration, w0, and the pH on the kinetic parameters and the maximum yields. For dipeptide synthesis, we had to add an excess of DCC with the substrates because of the side reactions of Cbz-Phe. From the pH dependency of the reactivity, a partially cationic form of Leu was better for a synthesis reaction because of the enrichment of Leu at the interface by anionic AOT. The optimum water content on the dipeptide synthesis was w0 = 28 due to the competition of the peptide synthesis and the side reactions. The maximum yield of Cbz-Phe-Leu was 0.565 at 80 h under optimum experimental conditions.

scholarly journals Structures of cell wall arabinosyltransferases with the anti-tuberculosis drug ethambutol

Science ◽  
2020 ◽  
Vol 368 (6496) ◽  
pp. 1211-1219 ◽  
Author(s):  
Lu Zhang ◽  
Yao Zhao ◽  
Yan Gao ◽  
Lijie Wu ◽  
Ruogu Gao ◽  
...  
Keyword(s):  
Cell Wall ◽  
Active Site ◽  
Structural Basis ◽  
Drug Resistant ◽  
Cell Wall Synthesis ◽  
X Ray ◽  
Cryo Electron Microscopy ◽  
Donor And Acceptor ◽  
Biochemical Function ◽  
Glycosyl Donor

The arabinosyltransferases EmbA, EmbB, and EmbC are involved in Mycobacterium tuberculosis cell wall synthesis and are recognized as targets for the anti-tuberculosis drug ethambutol. In this study, we determined cryo–electron microscopy and x-ray crystal structures of mycobacterial EmbA-EmbB and EmbC-EmbC complexes in the presence of their glycosyl donor and acceptor substrates and with ethambutol. These structures show how the donor and acceptor substrates bind in the active site and how ethambutol inhibits arabinosyltransferases by binding to the same site as both substrates in EmbB and EmbC. Most drug-resistant mutations are located near the ethambutol binding site. Collectively, our work provides a structural basis for understanding the biochemical function and inhibition of arabinosyltransferases and the development of new anti-tuberculosis agents.

A kinetic colorimetric assay of gamma-glutamyltransferase.

1986 ◽  
Vol 32 (8) ◽  
pp. 1581-1584 ◽  
Author(s):  
P Fossati ◽  
G V Melzi d'Eril ◽  
G Tarenghi ◽  
L Prencipe ◽  
G Berti
Keyword(s):  
Dynamic Range ◽  
Colorimetric Assay ◽  
Colorimetric Method ◽  
Volume Ratio ◽  
Ascorbate Oxidase ◽  
Good Precision ◽  
Gamma Glutamyltransferase ◽  
Gamma Glutamyl ◽  
Donor Substrate ◽  
Donor And Acceptor

Abstract We have explored a kinetic colorimetric method for measuring gamma-glutamyltransferase (EC 2.3.2.2) activity in serum, using L-gamma-glutamyl-3,5-dibromo-4-hydroxyanilide and glycylglycine as donor and acceptor substrates. The released product, 3,5-dibromo-4-hydroxyaniline, reacts with 2,5-dimethylphenol to produce a blue quinone monoimine in the presence of ascorbate oxidase (EC 1.10.3.3). This dye has peak absorption at 610 nm, whereas the donor substrate shows negligible absorption throughout the visible spectrum. The reaction can be run with all the reagents in a single working solution with serum as starter, or with the substrate solution as starting reagent. The sample/reagent volume ratio is 1:24. Adaptation of the method to several automated instruments gave good precision in all cases. Comparison with a method in which L-gamma-glutamyl-3-carboxy-4-nitroanilide is the donor substrate showed good correlation of results (r greater than or equal to 0.987). The dynamic range of the method exceeds the upper limits of the reference intervals for men (9-33 U/L) and women (8-25 U/L) by at least 18-fold.

Kinetic properties of gamma-glutamyltransferase from human liver.

1980 ◽  
Vol 26 (12) ◽  
pp. 1688-1693 ◽  
Author(s):  
C PetitClerc ◽  
F Shiele ◽  
D Bagrel ◽  
A Mahassen ◽  
G Siest
Keyword(s):  
Human Liver ◽  
Kinetic Properties ◽  
Major Pathway ◽  
Gamma Glutamyltransferase ◽  
Donor Substrate ◽  
Rate Limiting Step ◽  
Ph Dependency ◽  
Donor And Acceptor ◽  
Heavy Form ◽  
Rate Limiting

Abstract We studied the kinetic properties of purified "heavy" form of human liver gamma-glutamyltransferase (EC 2.3.2.2) in the presence and absence of the acceptor substrate glycylglycine under Vmax conditions and as a function of pH. gamma-Glutamyl carboxynitroanilide was used as the donor substrate. Our data suggest that hydrolysis of donor substrate is the major pathway in the absence of acceptor. Autotransfer, if it occurs, is not important. Hydrolysis and transfer reactions have different pH profiles both for Vmax and Km. The pH dependency of Vmax and Km for both the hydrolase and the transferase reactions most probably reflects a change in the rate-limiting step: deacylation of the enzyme at acidic pH and acylation at alkaline pH. Negative cooperativity, observed for both donor and acceptor substrates near neutral pH, is interpreted in terms of more than one active site per dimer for each substrate.

Synthesis of a New Type ofd-Mannosamine Glycosyl Donor and Acceptor and their Use for the Preparation of Oligosaccharides Consisting ofd-Mannosamine Units Linked by α(1→4)-Glycosidic Bonds

Synthesis ◽  
2008 ◽  
Vol 2008 (16) ◽  
pp. 2610-2616 ◽  
Author(s):  
Miroslav Ledvina ◽  
Matyáš Turský ◽  
Jan Veselý ◽  
Iva Tišlerová ◽  
Tomáš Trnka
Keyword(s):  
Glycosidic Bonds ◽  
Donor And Acceptor ◽  
New Type ◽  
Glycosyl Donor

scholarly journals Research Progress in Enzymatic Synthesis of Vitamin E Ester Derivatives

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 739
Author(s):  
Zhiqiang Zou ◽  
Lingmei Dai ◽  
Dehua Liu ◽  
Wei Du
Keyword(s):  
Vitamin E ◽  
Enzymatic Synthesis ◽  
Catalytic Efficiency ◽  
Research Progress ◽  
Acyl Donor ◽  
Environmental Friendliness ◽  
Donor And Acceptor ◽  
Improved Stability ◽  
Enzymatic Acylation ◽  
Reaction Media

Vitamin E is easily oxidized by light, air, oxidizing agents and heat, limiting its application in many ways. Compared to vitamin E, vitamin E ester derivatives exhibit improved stability and a stronger antioxidant capacity, and even gain new biological functions. In recent years, enzymatic synthesis of vitamin E ester derivatives has received increasing attention due to its environmental friendliness, high catalytic efficiency, and inherent selectivity. This paper reviews the related progress of lipase-mediated preparation of vitamin E ester derivatives. The function of different vitamin E ester derivatives, and the main factors influencing the enzymatic acylation process, including enzyme species, acyl donor and acceptor, reaction media and water activity, are summarized in this paper. Finally, the perspective of lipase-catalyzed synthesis of vitamin E ester derivatives is also discussed.

scholarly journals Intramolecular glycosylation

2017 ◽  
Vol 13 ◽  
pp. 2028-2048 ◽  
Author(s):  
Xiao G Jia ◽  
Alexei V Demchenko
Keyword(s):  
Review Article ◽  
Donor And Acceptor ◽  
Leaving Group ◽  
Glycosyl Donor

Carbohydrate oligomers remain challenging targets for chemists due to the requirement for elaborate protecting and leaving group manipulations, functionalization, tedious purification, and sophisticated characterization. Achieving high stereocontrol in glycosylation reactions is arguably the major hurdle that chemists experience. This review article overviews methods for intramolecular glycosylation reactions wherein the facial stereoselectivity is achieved by tethering of the glycosyl donor and acceptor counterparts.

scholarly journals Regioselective Silyl/Acetate Exchange of Disaccharides Yields Advanced Glycosyl Donor and Acceptor Precursors

2013 ◽  
Vol 78 (19) ◽  
pp. 9677-9688 ◽  
Author(s):  
Hsiao-Wu Hsieh ◽  
Matthew W. Schombs ◽  
Mark A. Witschi ◽  
Jacquelyn Gervay-Hague
Keyword(s):  
Donor And Acceptor ◽  
Glycosyl Donor
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