A
novel gene defining a novel
enzyme in the UDP-D-
galactose: b-N-acetyl-
glucosamine β-1,4-
galactosyltransferase family, termed β4Gal-T2, with unique enzymatic properties is disclosed. The enzymatic activity of β4Gal-T2 is shown to be distinct from that of previously identified enzymes of this
gene family. The invention discloses isolated
DNA molecules and
DNA constructs encoding β4Gal-T2 and derivatives thereof by way of
amino acid deletion, substitution or
insertion exhibiting β4Gal-T2 activity, as well as
cloning and expression vectors including such
DNA, cells transfected with the vectors, and recombinant methods for providing β4Gal-T2. The
enzyme β4Gal-T2 and β4Gal-T2-active derivatives thereof are disclosed, in particular soluble derivatives comprising the catalytically
active domain of β4Gal-T2. Further, the invention discloses methods of obtaining β-1,4-galactosyl glycosylated saccharides, glycopeptides or glycoproteins by use of an enzymically active β4Gal-T2
protein or
fusion protein thereof or by using cells stably transfected with a vector including
DNA encoding an enzymatically active β4Gal-T2
protein as an expression
system for recombinant production of such glycopeptides or glycoproteins. Also a method for the identification of DNA sequence variations in the β4Gal-T2
gene by isolating DNA from a patient, amplifying β4Gal-T2-coding exons by PCR, and detecting the presence of DNA
sequence variation, are disclosed.