Branch specificity of β-d-galactosidase from Escherichia coli

Eijnden, Dirk H. van den; Blanken, Willem M.; Vliet, Anja van

doi:10.1016/s0008-6215(00)90352-5

Cited by 24 publications

(30 citation statements)

References 19 publications

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“…A second orthogonal strategy for branch specific modification involved the selective removal of the galactoside at the MGAT1 arm of 7 . This was achieved using a galactosidase from E. coli 29 to give 9 , which has a terminal GlcNAc and LacNAc moiety at the MGAT1 and MGAT2 antennae, respectively. Many glycosyltransferases modify LacNAc but not terminal GlcNAc, thus it was possible to first elaborate the MGAT2 arm without affecting the MGAT1 arm.…”

Section: Resultsmentioning

confidence: 99%

Streamlining the chemoenzymatic synthesis of complex N-glycans by a stop and go strategy

et al. 2018

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Contemporary chemoenzymatic approaches can provide highly complex multi-antennary N -linked glycans. These procedures are, however, very demanding and typically involve as many as 100 chemical steps to prepare advanced intermediates that can be diversified by glycosyltransferases in a branch selective manner to give asymmetrical structures commonly found in Nature. Only highly specialized laboratories can perform such syntheses, which greatly hampers progress in glycoscience. Here we describe a biomimetic approach in which a readily available bi-antennary glycopeptide can be converted in 10 or fewer chemical and enzymatic steps into multi-antennary N -glycans that at each arm can be uniquely extended by glycosyltransferases to give access to highly complex asymmetrically branched N -glycans. A key feature of our approach is the installation of additional branching points using recombinant MGAT4 and MGAT5 in combination with unnatural sugar donors. At an appropriate point in the enzymatic synthesis, the unnatural monosaccharides can be converted into their natural counterpart allowing each arm to be elaborated into a unique appendage.

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Section: Resultsmentioning

confidence: 99%

Streamlining the chemoenzymatic synthesis of complex N-glycans by a stop and go strategy

et al. 2018

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“…17 Interestingly, LacZ also had a branch preference towards Galβ1,4-GlcNAcβ1,6-(Galβ1,4-GlcNAcβ1,3-)Gal (prefers β1,6-GlcNAc branch) but not to Galβ1,4-GlcNAcβ1,6-(Galβ1,4-GlcNAcβ1,3-)Galβ1,4-GlcNAc. 17–18 For this reason, we first performed a substrate specificity assay of LacZ towards a pair of N -glycan isomers N111 and N211 (Fig. 1).…”

Section: Selective Degalactosylation Of N001mentioning

confidence: 95%

An enzymatic strategy to asymmetrically branched N-glycans

et al. 2017

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An enzymatic strategy was developed to generate asymmetrically branched N-glycans from natural sources by using a panel of glycosidases and glycosyltransferases. Briefly, LacZ β-galactosidase was employed to selectively trim symmetrically branched N-glycans isolated from bovine fetuin. The yielding stuctures were then converted to asymetrically branched core structures by robust glycosyltransferase for further extension.

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“…This is probably due to the fact that not all epiglycanin molecules were capped, even though they did react with the capping mAb, as can be seen in Fig. 1 C. Epiglycanin is very heterogeneous with respect to its glycosylation state (Codington et al, 1975(Codington et al, , 1986Van den Eijnden et al, 1986). It is therefore conceivable that molecules containing fewer of the repeated carbohydrate epitopes are capped less efficiently.…”

Section: Enzymatic Removal Of Epiglycanin From the Cell Surface Resulmentioning

confidence: 98%

The mucin epiglycanin on TA3/Ha carcinoma cells prevents alpha 6 beta 4-mediated adhesion to laminin and kalinin and E-cadherin-mediated cell-cell interaction.

Kemperman

Wijnands

Wesseling

et al. 1994

The Journal of Cell Biology

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Abstract. TA3/Ha murine mammary carcinoma cells grow in suspension, do not adhere to extracellular matrix molecules, but do adhere to hepatocytes and form liver metastases upon intraportal injection. Recently we showed that the integrin ottfl4 on the TA3/Ha cells is involved in adhesion to hepatocytes. However, despite high cell surface levels of o~6B4, TA3/Ha cells do not adhere to the ot6~4 ligands laminin and kalinin. Here we show that this is due to the mucin epiglycanin that is highly expressed on TA3/Ha cells. Some monoclonal antibodies generated against epiglycanin induced capping of most of the epiglycanin molecules. TA3/Ha cells treated with these mAb did adhere to laminin and kalinin, and an epithelial monolayer was formed on kalinin, with ot6~4 localized in HDl-containing hemidesmosome-like structures and E-cadherin at the cell-cell contact sites. Similar results were obtained after treatment of TA3/Ha cells with O-sialoglycoprotein endopeptidase which removes all epiglycanin. In addition, the enzyme induced E-cadherin-mediated cell-cell aggregation. Both treatments also enhanced the adhesion to hepatocytes, but given the potent antiadhesive effect of epiglycanin it is remarkable that nontreated TA3/Ha cells adhere to hepatocytes at all. We found that during this interaction, epiglycanin was redistributed. We conclude that epiglycanin can completely prevent both intercellular and matrix adhesion, but that this effect can be overcome in certain intercellular interactions because of the induced redistribution of the mucin.

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Branch specificity of β-d-galactosidase from Escherichia coli

Cited by 24 publications

References 19 publications

Streamlining the chemoenzymatic synthesis of complex N-glycans by a stop and go strategy

Streamlining the chemoenzymatic synthesis of complex N-glycans by a stop and go strategy

An enzymatic strategy to asymmetrically branched N-glycans

The mucin epiglycanin on TA3/Ha carcinoma cells prevents alpha 6 beta 4-mediated adhesion to laminin and kalinin and E-cadherin-mediated cell-cell interaction.

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