[摘要]：UDP-galactopyranose mutase (UGM) is a flavin-containing enzyme that catalyzes the conversion of UDP-galactopyranose to UDP-galactofuranose. the precursor of galactofuranose, which is an important cell wall component in Aspergillus fumigatus and other pathogenic microbes A fumigatus UGM (AfUGM) was expressed in Escherichia coli and purified to homogeneity The enzyme was shown to function as a homotetramer by size-exclusion chromatography and to contain similar to 50% of the flavin in the active (reduced form. A k(cat) value of 72 +/- 4 s(-1) and a K-M value of 110 +/- 15 mu M were determined with UDP-galactofuranose as substrate In the oxidized state. AfUGM does not bind UDP-galactopyranose. while UDP and UDP-glucose bind with K-d values of 33 +/- 9 mu M and 90 +/- 30 mu M. respectively Functional and structural differences between the bacterial and eukaryotic UGMs are discussed Published by Elsevier Inc
