Abstract
Tammar wallaby ( Macropus eugenii) mammary glands contain a UDP-GlcNAc: Gal β1→3Gal β1→4Glc β1→6- N- acetylglucosaminyltransferase (GlcNAcT) whose activity has been characterized with respect to the effect of pH, apparent K m for acceptor, effects of bivalent metal ions, acceptor specificity and identity of products. The enzyme did not show an absolute requirement for any bivalent metal ion but its activity was increased markedly by Mg 2+, Ca 2+ and Ba 2+ and, to a lesser extent, by Mn 2+. When Gal β1→3Gal β1→4Glc was used as acceptor, the product was Gal β1→3[GlcNAc β1→6]Gal β1→5Glc. With Gal β1→3Gal β1→3Gal β1→4Glc as acceptor, the product was shown, by 1H-NMR spectroscopy and exo-β-galacosidase digestion, to be a novel pentasaccharide with the structure Gal β1→3[GlcNAc β1→3Gal β1→4Glc, suggesting that the enzyme recognises the non-reducing end of the acceptor substrate, rather than the reducing end.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
