TY - JOUR
T1 - Artificial glycosyl phosphorylases
AU - Rousseau, Cyril
AU - Ortega-Caballero, Fernando
AU - Nordstrøm, Lars Ulrik
AU - Christensen, Brian
AU - Petersen, Torben Ellebaek
AU - Bols, Mikael
PY - 2005/8/19
Y1 - 2005/8/19
N2 - α- and β-Cyclodextrin 6A,6Ddiacids (1 and 2), β-cyclodextrin-6monoacid (14), β-cyclodextrin 6,6 D-diO-sulfate (16) and β-cyclodextrin-6heptasulfate (19) were synthesised. Acids 1, 2 and 14 were made from perbenzylated α- or β-cyclodextrin, by diisobutylaluminum hydride (DIBAL)promoted debenzylation, oxidation and deprotection. Addition of molecular sieves was found to improve the debenzylation reaction. Sulfates 16 and 19 were made by sulfation of the appropriately partially protected derivatives and deprotection. Catalysis of 4-nitrophenyl glycoside cleavage by these cyclodextrin derivatives was studied. Compounds 1, 2 and 16 were found to catalyse the reaction, with the catalysis following Michaelis-Menten kinetics and depending first order on the phosphate concentration. In a phosphate buffer (0.5 M, 59 °C, pH 8.0), KM varied from 2-10 mM and the kcat/kuncat ratio from 80-1000 depending on the stereochemistry of the substrate and the catalyst, with 2 being the best catalyst and with the sulfated 16 also displaying catalytic ability. The monoacid 14 and the heptasulfate 19 were not catalytic.
AB - α- and β-Cyclodextrin 6A,6Ddiacids (1 and 2), β-cyclodextrin-6monoacid (14), β-cyclodextrin 6,6 D-diO-sulfate (16) and β-cyclodextrin-6heptasulfate (19) were synthesised. Acids 1, 2 and 14 were made from perbenzylated α- or β-cyclodextrin, by diisobutylaluminum hydride (DIBAL)promoted debenzylation, oxidation and deprotection. Addition of molecular sieves was found to improve the debenzylation reaction. Sulfates 16 and 19 were made by sulfation of the appropriately partially protected derivatives and deprotection. Catalysis of 4-nitrophenyl glycoside cleavage by these cyclodextrin derivatives was studied. Compounds 1, 2 and 16 were found to catalyse the reaction, with the catalysis following Michaelis-Menten kinetics and depending first order on the phosphate concentration. In a phosphate buffer (0.5 M, 59 °C, pH 8.0), KM varied from 2-10 mM and the kcat/kuncat ratio from 80-1000 depending on the stereochemistry of the substrate and the catalyst, with 2 being the best catalyst and with the sulfated 16 also displaying catalytic ability. The monoacid 14 and the heptasulfate 19 were not catalytic.
KW - Artificial enzymes
KW - Cyclodextrins
KW - Glycosides
KW - Hydrolysis
KW - Kinetics
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U2 - 10.1002/chem.200500364
DO - 10.1002/chem.200500364
M3 - Article
C2 - 15981287
AN - SCOPUS:24344449627
SN - 0947-6539
VL - 11
SP - 5094
EP - 5101
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 17
ER -