Enzymatically oxidized lactose and derivatives thereof as potential protein cross-linkers

Biocatalytic Production of Amino Carbohydrates through Oxidoreductase and Transaminase Cascades

“…[61] The activity of FgrGaOx toward 50 mm 2e was determined with the ABTS assay to be 50.1 AE 4.9 Umg À1 enzyme,w hich is about 10 %o f that of FgrGaOx toward 2a.F ormation of the corresponding bifunctionali ntermediate product 2f was confirmed by ESI-Q-TOFM S( Figure 1C), and nearly complete conversion in the subsequent transaminase reaction wasv erified by HPAEC-PAD ( Figure S3 in the Supporting Information).D espite this, diamine 2g was not detected by mass spectrometry,p ossibly Scheme1.Biocatalytic cascades to aminated carbohydrates. [61] The activity of FgrGaOx toward 50 mm 2e was determined with the ABTS assay to be 50.1 AE 4.9 Umg À1 enzyme,w hich is about 10 %o f that of FgrGaOx toward 2a.F ormation of the corresponding bifunctionali ntermediate product 2f was confirmed by ESI-Q-TOFM S( Figure 1C), and nearly complete conversion in the subsequent transaminase reaction wasv erified by HPAEC-PAD ( Figure S3 in the Supporting Information).D espite this, diamine 2g was not detected by mass spectrometry,p ossibly Scheme1.Biocatalytic cascades to aminated carbohydrates.…”

“…Having confirmedt he production of 2e,w ev entured to produce diamine 2g,w hich is expected to permitc arbohydrate coupling through imine bond formation. [61] The activity of FgrGaOx toward 50 mm 2e was determined with the ABTS assay to be 50.1 AE 4.9 Umg À1 enzyme,w hich is about 10 %o f that of FgrGaOx toward 2a.F ormation of the corresponding bifunctionali ntermediate product 2f was confirmed by ESI-Q-TOFM S( Figure 1C), and nearly complete conversion in the subsequent transaminase reaction wasv erified by HPAEC-PAD ( Figure S3 in the Supporting Information).D espite this, diamine 2g was not detected by mass spectrometry,p ossibly Scheme1.Biocatalytic cascades to aminated carbohydrates. A) Oxidationofad-galactosyl subunit on ac arbohydrate molecule to 6-aldo-d-galactosyl( 2b-6b;see Ta ble S1 for structures of 3b-6b)b yFgrGaOx and subsequent amination of the aldehydeg roup to 6- [53] and subsequent amination of ketone 2d to amine 2e by Cvi-w-TA.…”

Oxidation with galactose oxidase: Multifunctional enzymatic catalysis

“…The aldehyde product was purified and isolated with preparative TLC [26]. The conversions of lactose and raffinose were similar to the M a n u s c r i p t 10 conversions of monosaccharides [33,47], for example, Van Wijk et al obtained oxidized lactose dialdehyde with quantitative yield [47].…”

“…Most simply, the reactions were conducted in an open flask with stirring [26,40]. In an effort to further increase oxygen concentration in reaction mixtures, an O 2 balloon has been attached to the reaction flask [3], and O 2 gas has been flushed into reaction media either continuously [33] or in short periods [31,47]. However, the impact of these various techniques on product yield did not significantly differ (Table 1 and 2).…”

Expression, purification, and characterization of galactose oxidase of Fusarium sambucinum in E. coli

“…Furthermore, GalOx has been used in biosensors for the measurement of galactose and its derivatives in biological fluids [25] , to label galactose residues in glycoconjugates [26] , and for the induction of interferon in human lymphocyte culture [27,28] . GalOx is viewed as a competitive and cost-effective catalyst compared to chemical conversion for the manufacturing of fine chemicals for pharmaceutical purposes or in food industry, for example GalOx was used for conversion of sugars like d -galactose to food-grade cross-linking agents [29–32] . Another important application for GalOx is the modification of cell surface carbohydrates and has been used in cell labeling studies and histochemical staining [19] .…”