Oxidation with galactose oxidase: Multifunctional enzymatic catalysis

Parikka, Kirsti; Master, Emma R.; Tenkanen, Maija

doi:10.1016/j.molcatb.2015.06.006

Cited by 73 publications

(80 citation statements)

References 82 publications

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“…Galactose oxidase (GO) is a secretory fungal enzyme that catalyzes the 2e − oxidation of primary alcohols to aldehydes (Scheme 1A) 1–5 and some evidence suggests GO may also capable of the subsequent slower 2e − oxidation to carboxylic acids (Scheme 1B). 6,7 Each of these reactions is coupled to the 2e − reduction of O 2 to H 2 O 2 .…”

Section: Introductionmentioning

confidence: 99%

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O₂ Activation in Cofactor Biogenesis

et al. 2016

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Galactose oxidase (GO) is a copper-dependent enzyme that accomplishes 2e− substrate oxidation by pairing a single copper with an unusual cysteinylated tyrosine (Cys-Tyr) redox cofactor. Previous studies have demonstrated that the post-translational biogenesis of Cys-Tyr is copper- and O2-dependent, resulting in a self-processing enzyme system. To investigate the mechanism of cofactor biogenesis in GO, the active-site structure of Cu(I)-loaded GO was determined using X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy, and density-functional theory (DFT) calculations were performed on this model. Our results show that the active-site tyrosine lowers the Cu potential to enable the thermodynamically unfavorable 1e− reduction of O2, and the resulting Cu(II)-O2•− is activated towards H-atom abstraction from cysteine. The final step of biogenesis is a concerted reaction involving coordinated Tyr ring deprotonation where Cu(II) coordination enables formation of the Cys-Tyr crosslink. These spectroscopic and computational results highlight the role of the Cu(I) in enabling O2 activation by 1e− and the role of the resulting Cu(II) in enabling substrate activation for biogenesis.

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Section: Introductionmentioning

confidence: 99%

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O₂ Activation in Cofactor Biogenesis

et al. 2016

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“…[13] Based on the specificity of the enzymatic reaction, our experimental design is shown in Figure 1. Galactose oxidase was employed to catalyze the oxidation of the Tn antigen on glycopeptides with strict regioselectivity, that is, only for GalNAc [14] but not GlcNAc.…”

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confidence: 99%

Specific Identification of Glycoproteins Bearing the Tn Antigen in Human Cells

Zheng

Xiao

2017

Angew Chem Int Ed

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Glycoproteins contain a wealth of valuable information regarding the development and disease status of cells. In cancer cells, some glycans (such as the Tn antigen) are highly up-regulated, but this remains largely unknown for glycoproteins with a particular glycan. Herein, an innovative method combining enzymatic and chemical reactions was first designed to enrich glycoproteins with the Tn antigen. Using synthetic glycopeptides with O-GalNAc (the Tn antigen) or O-GlcNAc, we demonstrated that the method is selective for glycopeptides with O-GalNAc and can distinguish between these two modifications. The diagnostic ions from the tagged O-GalNAc further confirmed the effectiveness of the method and confidence in the identification of glycopeptides with the Tn antigen by mass spectrometry. Using this method, we identified 96 glycoproteins with the Tn antigen in Jurkat cells. The method can be extensively applied in biological and biomedical research.

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“…: depolymerization with carbohydrolases or lyases (Cheroni, Formantici, & Galante, 2010;Delattre et al, 2015;Tavernier et al, 2008), debranching with ␣-glycosidase, oxidation with oxidases (i.e., laccase, peroxidase, galactose oxidase), but also for the "elimination" of insoluble proteins with proteases (Baldaro et al, 2012). Enzymatic oxidation of guar GM has been described using either a wild type galactose oxidase (GaO), followed by reductive amination (Hall & Yalpani, 1980) or by halogen oxidation (Frollini, Reed, Milas, & Rinaudo, 1995), or with a highly engineered GaO by Parikka and co-workers (Delagrave et al, 2001(Delagrave et al, , 2002Ghafar et al, 2015;Leppanen et al, 2010;Mikkonen et al, 2014;Parikka & Tenkanen, 2009;Parikka et al, 2010Parikka et al, , 2012Parikka, Master, & Tenkanen, 2015). More generally, oxidation of polysaccharides with the enzyme laccase can generate reactive groups (e.g., carbonyls, carboxyls) on cellulose , on starch (Viikari, Niku-Paavola, et al, 1999), on pullulan (Jetten et al, 2000), and on guar galactomannan (Lavazza et al, 2011).…”

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confidence: 99%

An aerogel obtained from chemo-enzymatically oxidized fenugreek galactomannans as a versatile delivery system

Rossi

Campia

Merlini

et al. 2016

Carbohydrate Polymers

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a b s t r a c tWe describe a new aerogel obtained from laccase-oxidized galactomannans of the leguminous plant fenugreek (Trigonella foenum-graecum) and suggest its potential practical use.Laccase/TEMPO oxidation of fenugreek in aqueous solution caused a viscosity increase of over 15-fold. A structured, elastic, stable hydrogel was generated, due to formation of carbonyl groups from primary OH of galactose side units and subsequent establishment of hemiacetalic bonds with available free hydroxyl groups.Upon lyophilization of this hydrogel, a water-insoluble aerogel was obtained (EOLFG), capable of uptaking aqueous or organic solvents over 20 times its own weight. The material was characterized by scanning electron microscopy, FT-IR, elemental analysis and 13 C CP-MAS NMR spectroscopy and its mechanical properties were investigated.To test the EOLFG as a delivery system, the anti-microbial enzyme lysozyme was used as model active principle. Lysozyme was added before or after formation of the aerogel, entrapped or absorbed in the gel, retained and released in active form, as proven by its hydrolytic glycosidase activity on lyophilized Micrococcus lysodeikticus cells wall peptidoglycans.This new biomaterial, composed of a chemo-enzymatically modified plant polysaccharide, might represent a versatile, biocompatible "delivery system" of active principles in food and non-food products.

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Oxidation with galactose oxidase: Multifunctional enzymatic catalysis

Cited by 73 publications

References 82 publications

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O₂ Activation in Cofactor Biogenesis

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O₂ Activation in Cofactor Biogenesis

Specific Identification of Glycoproteins Bearing the Tn Antigen in Human Cells

An aerogel obtained from chemo-enzymatically oxidized fenugreek galactomannans as a versatile delivery system

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Oxidation with galactose oxidase: Multifunctional enzymatic catalysis

Cited by 73 publications

References 82 publications

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O2 Activation in Cofactor Biogenesis

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O2 Activation in Cofactor Biogenesis

Specific Identification of Glycoproteins Bearing the Tn Antigen in Human Cells

An aerogel obtained from chemo-enzymatically oxidized fenugreek galactomannans as a versatile delivery system

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Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O₂ Activation in Cofactor Biogenesis

Structure of the Reduced Copper Active Site in Preprocessed Galactose Oxidase: Ligand Tuning for One-Electron O₂ Activation in Cofactor Biogenesis