Ma. Williams et al., LARGE-SCALE EXPRESSION OF RECOMBINANT SIALYTTRANSFERASES AND COMPARISON OF THEIR KINETIC-PROPERTIES WITH NATIVE ENZYMES, Glycoconjugate journal, 12(6), 1995, pp. 755-761
Values of K-m were determined for three purified sialyltransferases an
d the corresponding recombinant enzymes. The enzymes were Gal beta 1-4
,GlcNAc alpha 2-6sialyltransferase and Gal beta 1-3(4)GlcNAc alpha 2-3
sialyltransferase from rat liver; these enzymes are responsible for th
e attachment of sialic acid to N-linked oligosaccharide chains; and th
e Gal beta 1-3GalNAc alpha 2-3sialyltransferase from porcine submaxill
ary gland that is responsible for the attachment of sialic acid to O-l
inked glycoproteins and glycolipids. A procedure for the large scale e
xpression of active sialyltransferases from recombinant baculovirus-in
fected insect cells is described. For the liver enzymes values of K-m
were determined using rat and human asialo(alpha 1) acid glycoprotein
and N-acetyllactosamine as variable substrates; lacto-N-tetraose was a
lso used with the Gal beta 1-3(4)GlcNAc alpha 2-3sialyltransferase. An
tifreeze glycoprotein was used as the macromolecular acceptor for the
porcine enzyme. Values for K-m were also determined using CMP-NeuAc as
the variable substrate.