Matches in SemOpenAlex for { <https://semopenalex.org/work/W2790728543> ?p ?o ?g. }
- W2790728543 abstract "It is known that eukaryotic cells have an envelope of carbohydrates – the glycocalyx – which plays a crucial role in cell-cell and cell-ligand interaction processes. Additionally, bacterial glycosylation patterns are in the spotlight. Carbohydrate structures influence inflammation, tomor formation and progression, infections and many other biological processes. Glycobiology is a science on the crossroads of chemistry and biology. Synthesis and analysis of carbohydrate structures demand the application of methods from both fields of science and beyond. Carbohydrates are on the one hand chemically similar, on the other hand its structure determination demands basic chemical methods like nuclear magnetic resonance (NMR) and mass spectroscopy (MS) or even their combination. Glycosyl transferases are carbohydrate-active enzymes and are of outstanding relevance in glycobiology. They are involved in the synthesis as well as the degradation and carbohydrate recognition.In this thesis novel oligosaccharides were synthesized by the consecutive action of two fructosyltransferases. The fructosyltransferases SacB from Bacillus megaterium transfers a fructosyl moiety to different acceptors (galactose, mannose, fucose and xylose). The fructosyltransferase Suc1 from Aspergillus niger synthesizes defined tri- and tetrasaccharides. These oligofructosides were examined concerning their immuno-stimulatory properties by a co-cultivation with human colorectal epithelial carcinoma cells (Caco-2). A test regarding the secretion of 25 different cytokines yielded a significantly high level of interleukin 8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1).The fructosyltransferase SacB from Bacillus megaterium was examined by a intensive mutagenesis study. By enzyme engineering, 27 variants were created on the basis of sequence alignments with fructosyltransferases from other organisms and the solved structure of the fructosyltransferase from Bacillus megaterium (in cooperation with Rebekka Biedendieck and Martin Gamer, Department of Microbiology, TU Braunschweig and Christian Strube, Helmholtz-Centre for Infection Research). The biochemical data of these variants proved their influence on the polysaccharide formation. The variants of the amino acids Y247, N252, K315 and K373 are not located in the active site, but have a clear impact on the poly- vs. oligosaccharide formation. In spite of their altered product spectrum, their kinetic data are similar to the wild-type SacB. On the basis of these examinations, the polymer vs. Oligosaccharide formation mechanism of glycosyltransferases became clearer.Furthermore, a sucrose isomerase from Protaminobacter rubrum was examined. Substrate engineering of this enzyme led to the synthesis of an isomaltulose analogue consisting of a galactose unit instead of glucose. The linkage was determined as alpha-(1,6) analogous to isomaltulose.Finally, chemically functionalized carbohydrates were synthesized and presented on the surface of eukaryotic cells by glycoengineering techniques. In this position they are specific targets on the surface of human larynx carcinoma cells (HEp-2) for further chemical modification. This was performed by the incorporation of azido-functionalized N-acetyl-glucosamine and alkyne-functionalized N-acetyl neuraminic acid. By “click chemistry” with alkynylated rhodamine or azido fluorescein, respectively, these modified carbohydrates were detected." @default.
- W2790728543 created "2018-03-29" @default.
- W2790728543 creator A5079143759 @default.
- W2790728543 date "2009-12-17" @default.
- W2790728543 modified "2023-09-23" @default.
- W2790728543 title "En Route to Tailor-made Oligosaccharides - Chemo-Enzymatic Synthesis and Physiological Functions of Novel Carbohydrate Structures" @default.
- W2790728543 cites W1525946619 @default.
- W2790728543 cites W1577270054 @default.
- W2790728543 cites W1806434068 @default.
- W2790728543 cites W1917934300 @default.
- W2790728543 cites W1928818161 @default.
- W2790728543 cites W1944745529 @default.
- W2790728543 cites W1966377219 @default.
- W2790728543 cites W1967539420 @default.
- W2790728543 cites W1968222033 @default.
- W2790728543 cites W1968305011 @default.
- W2790728543 cites W1968760213 @default.
- W2790728543 cites W1971635303 @default.
- W2790728543 cites W1972056015 @default.
- W2790728543 cites W1973136622 @default.
- W2790728543 cites W1975973447 @default.
- W2790728543 cites W1978107100 @default.
- W2790728543 cites W1979366610 @default.
- W2790728543 cites W1987250042 @default.
- W2790728543 cites W1987416060 @default.
- W2790728543 cites W1987419931 @default.
- W2790728543 cites W1988515297 @default.
- W2790728543 cites W1989237374 @default.
- W2790728543 cites W1989331104 @default.
- W2790728543 cites W1993042746 @default.
- W2790728543 cites W1997099073 @default.
- W2790728543 cites W1997334220 @default.
- W2790728543 cites W1997716632 @default.
- W2790728543 cites W1998476644 @default.
- W2790728543 cites W2001038197 @default.
- W2790728543 cites W2001088901 @default.
- W2790728543 cites W2002496324 @default.
- W2790728543 cites W2005767394 @default.
- W2790728543 cites W2014462918 @default.
- W2790728543 cites W2015509108 @default.
- W2790728543 cites W2016415261 @default.
- W2790728543 cites W2018101456 @default.
- W2790728543 cites W2021821907 @default.
- W2790728543 cites W2022170433 @default.
- W2790728543 cites W2023610999 @default.
- W2790728543 cites W2024672069 @default.
- W2790728543 cites W2026667768 @default.
- W2790728543 cites W2028355094 @default.
- W2790728543 cites W2028410320 @default.
- W2790728543 cites W2031782630 @default.
- W2790728543 cites W2034537831 @default.
- W2790728543 cites W2034911992 @default.
- W2790728543 cites W2036777897 @default.
- W2790728543 cites W2037466942 @default.
- W2790728543 cites W2037796752 @default.
- W2790728543 cites W2039735007 @default.
- W2790728543 cites W2040514209 @default.
- W2790728543 cites W2041555931 @default.
- W2790728543 cites W2042510427 @default.
- W2790728543 cites W2044509450 @default.
- W2790728543 cites W2044512906 @default.
- W2790728543 cites W2045678518 @default.
- W2790728543 cites W2047719515 @default.
- W2790728543 cites W2048470673 @default.
- W2790728543 cites W2050255668 @default.
- W2790728543 cites W2052423941 @default.
- W2790728543 cites W2052731133 @default.
- W2790728543 cites W2054580315 @default.
- W2790728543 cites W2055161068 @default.
- W2790728543 cites W2057350048 @default.
- W2790728543 cites W2063775942 @default.
- W2790728543 cites W2065609269 @default.
- W2790728543 cites W2068498238 @default.
- W2790728543 cites W2068623317 @default.
- W2790728543 cites W2074737756 @default.
- W2790728543 cites W2077827644 @default.
- W2790728543 cites W2078951307 @default.
- W2790728543 cites W2079737908 @default.
- W2790728543 cites W2082102215 @default.
- W2790728543 cites W2082406335 @default.
- W2790728543 cites W2084037902 @default.
- W2790728543 cites W2084375116 @default.
- W2790728543 cites W2085028384 @default.
- W2790728543 cites W2088293716 @default.
- W2790728543 cites W2088497317 @default.
- W2790728543 cites W2089118371 @default.
- W2790728543 cites W2090183771 @default.
- W2790728543 cites W2094897835 @default.
- W2790728543 cites W2096246094 @default.
- W2790728543 cites W2099402486 @default.
- W2790728543 cites W2099675490 @default.
- W2790728543 cites W2100882223 @default.
- W2790728543 cites W2103635418 @default.
- W2790728543 cites W2103848393 @default.
- W2790728543 cites W2104294582 @default.
- W2790728543 cites W2107373516 @default.
- W2790728543 cites W2108929776 @default.
- W2790728543 cites W2109399675 @default.
- W2790728543 cites W2110850919 @default.
- W2790728543 cites W2111051779 @default.