Probing UDP-galactopyranose mutase binding pocket: a dramatic effect on substitution of the 6-position of UDP-galactofuranose.
UDP-galactopyranose mutase (UGM) catalyzes the isomerization of UDP-galactopyranose (UDP-Galp) into UDP-galactofuranose (UDP-Galf), an essential step of the mycobacterial cell wall biosynthesis. UDP-(6-deoxy-6-fluoro)-D-galactofuranose 1 was tested as substrate of UGM. Turnover could be observed by HPLC. The k(cat) (7.4s(-1)) and the K(m) (24 mM) of 1 were thus measured and compared with those of UDP-Galf and other fluorinated analogs. The presence of the fluorine atom at the 6-position had a moderate effect on the rate of the reaction but a huge one on the interactions between the enzyme and its substrate. This result demonstrated that key interactions occur at the vicinity of the 6-position of UDP-galactose in the Michaelis complex.
Eppe
Guillaume
G
University of Namur (FUNDP), Département de Chimie, Laboratoire de Chimie Bio-Organique, rue de Bruxelles 61, B-5000 Namur, Belgium.
Peltier
Pauline
P
Daniellou
Richard
R
Nugier-Chauvin
Caroline
C
Ferrières
Vincent
V
Vincent
Stéphane P
SP
D002241:Carbohydrates / Q000737:chemistry; D002384:Catalysis; D002473:Cell Wall / Q000378:metabolism; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D015195:Drug Design; D005461:Fluorine / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D005690:Galactose / Q000031:analogs & derivatives* / Q000737:chemistry; D019751:Intramolecular Transferases / Q000737:chemistry*; D007700:Kinetics; D008968:Molecular Conformation; D009161:Mycobacterium / Q000378:metabolism; D011485:Protein Binding; D014530:Uridine Diphosphate / Q000031:analogs & derivatives* / Q000737:chemistry
D002241:Carbohydrates; D005663:Furans; C104136:uridine diphosphate galactofuranose; D005461:Fluorine; D014530:Uridine Diphosphate; D019751:Intramolecular Transferases; C098051:UDP-galactopyranose mutase; D005690:Galactose