TY  - JOUR
A1  - Homann, Arne
A1  - Timm, Malte
A1  - Seibel, Jürgen
T1  - Chemo-enzymatic synthesis and in vitro cytokine profiling of tailor-made oligofructosides
N2  - Background It is well known that carbohydrates play fundamental roles in cell signaling and infection processes as well as tumor formation and progression. However, the interaction pathways and cellular receptors targeted by carbohydrates and glycoconjugates remain poorly examined and understood. This lack of research stems, at least to a major part, from accessibility problems of large, branched oligosaccharides. Results To test glycan - cell interactions in vitro, a variety of tailored oligosaccharides was synthesized chemo-enzymatically. Glycosyltransferases from the GRAS organisms Bacillus megaterium (SacB) and Aspergillus niger (Suc1) were used in this study. Substrate engineering of these glycosyltransferases generally acting on sucrose leads to the controlled formation of novel tailored di-, tri- and tetrasaccharides. Already industrially used as prebiotics in functional food, the immunogenic potential of novel oligosaccharides was characterized in this study. A differential secretion of CXCL8 and CCL2 was observed upon oligosaccharide co-cultivation with colorectal epithelial Caco-2 cells. Conclusion Pure carbohydrates are able to stimulate a cytokine response in human endothelial cells in vitro. The type and amount of cytokine secretion depends on the type of co-cultivated oligosaccharide.
KW  - Chemie
KW  - Oligofructoside
KW  - Glycosyltransferase
KW  - Suc1
KW  - Aspergillus niger
KW  - SacB
KW  - Bacillus megaterium
KW  - CXCL8 (IL-8)
KW  - CCL2 (MCP-1)
KW  - Caco-2
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76393
ER  - 
TY  - JOUR
A1  - Homann, Arne
A1  - Qamar, Riaz-ul
A1  - Serim, Sevnur
A1  - Dersch, Petra
A1  - Seibel, Juergen
T1  - Bioorthogonal metabolic glycoengineering of human larynx carcinoma (HEp-2) cells targeting sialic acid
N2  - Sialic acids are located at the termini of mammalian cell-surface glycostructures, which participate in essential interaction processes including adhesion of pathogens prior to infection and immunogenicity. Here we present the synthesis and bioorthogonal metabolic incorporation of the sialic acid analogue N-(1-oxohex-5-ynyl)neuraminic acid (Neu5Hex) into the cell-surface glycocalyx of a human larynx carcinoma cell line (HEp-2) and its fluorescence labelling by click chemistry.
KW  - Organische Chemie
KW  - bioorthogonal metabolic glycoengineering; click chemistry; sialic acid
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67806
ER  -