The action of alpha-mannosidase from Oerskovia sp. on the mannose-rich O-linked sugar chains of glycoproteins.
Alpha-mannosidase was isolated from the culture liquid of Oerskovia sp. The purified enzyme had a molecular mass of 480 kDa and comprises four identical subunits. The enzyme cleaves bonds in side chains of yeast mannan (Km = 0.08 mM, k(cat) = 1.02 micromol x min(-1) x mg(-1)) and reveals a low activity towards p-nitrophenyl alpha-D-mannopyranoside. The alpha-mannosidase is a Ca2+-dependent enzyme and is inhibited by EDTA. The enzyme possess no endo-mannosidase activity releasing only mannose in the reaction with the inversion of anomeric configuration and could be classified as exo-alpha-mannanase. The enzyme revealed a high deglycosylating activity towards the short mannose-rich O-linked carbohydrate chains of glycoproteins.
Bagiyan
F G
FG
Petersburg Nuclear Physics Institute, Molecular and Radiation Biophysics Division, St Petersburg, Russia.
Eneyskaya
E V
EV
Kulminskaya
A A
AA
Savel'ev
A N
AN
Shabalin
K A
KA
Neustroev
K N
KN
D000192:Actinomycetales / Q000201:enzymology*; D001665:Binding Sites; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008351:Mannans / Q000737:chemistry / Q000378:metabolism; D008358:Mannose / Q000737:chemistry; D008361:Mannosidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D043323:alpha-Mannosidase
D002241:Carbohydrates; D006023:Glycoproteins; D008351:Mannans; D008361:Mannosidases; D043323:alpha-Mannosidase; D008358:Mannose