Effect of organic cosolvents on the stability and activity of the beta-1,4-galactosyltransferase from bovine colostrum.
The influence of various organic cosolvents on the stability and activity of the beta-1,4-galactosyltransferase from bovine colostrum (GalT) and of its ancillary enzyme UDP-galactose-4'-epimerase has been investigated using the glucosylated alkaloid colchicoside (1) as a model substrate. It has been found that some cosolvents, such as Me2SO and MeOH, can be used up to 20% v/v without any influence on the performance of these enzymes, while others, such as tetrahydrofuran, rapidly inactivated GalT at concentrations as low as 5% v/v. These results have been exploited for the galactosylation of the poorly water soluble coumarinic glucoside fraxin (2).
Riva
S
S
Istituto di Chimica degli Ormoni, C.N.R., Milano, Italy. rivas@ico.mi.cnr.it
Sennino
B
B
Zambianchi
F
F
Danieli
B
B
Panza
L
L
D000818:Animals; D002417:Cattle; D003078:Colchicine / Q000031:analogs & derivatives / Q000378:metabolism; D003126:Colostrum / Q000201:enzymology*; D003374:Coumarins / Q000378:metabolism; D004795:Enzyme Stability / Q000187:drug effects; D005700:Galactosyltransferases / Q000378:metabolism*; D006027:Glycosides / Q000138:chemical synthesis; D006031:Glycosylation; D007768:Lactalbumin / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D012995:Solubility; D012997:Solvents / Q000494:pharmacology*; D014534:UDPglucose 4-Epimerase / Q000378:metabolism*; D014531:Uridine Diphosphate Galactose / Q000378:metabolism
D003374:Coumarins; D006027:Glycosides; D012997:Solvents; C008245:lactosides; D014531:Uridine Diphosphate Galactose; D007768:Lactalbumin; C014419:colchicoside; D005700:Galactosyltransferases; D014534:UDPglucose 4-Epimerase; D003078:Colchicine; C080614:fraxin