Identification and characterization of an alpha-mannosidase from Trypanosoma cruzi.
In this report we describe the first purification and characterization of the acid alpha-mannosidase from the human parasite Trypanosoma cruzi. The purified enzyme exhibited a native mol. wt of 240,000 Da and is apparently composed of four identical subunits of mol. wt 58,000 Da. Each of the four subunits contains one N-linked high-mannose-type oligosaccharide. The alpha-mannosidase exhibited a pH optimum of 3.5 and a pI of 5.9. This low pH optimum and the ability of swainsonine to inhibit its activity suggest that the alpha-mannosidase is a lysosomal enzyme. Antibodies against the T.cruzi enzyme did not react with mammalian lysosomal alpha-mannosidase and, conversely, antibody against a rat lysosomal alpha-mannosidase did not react with the T.cruzi enzyme. Thus, the T.cruzi enzyme appears to be distinct from its mammalian counterpart.
Swanson
P M
PM
Department of Medicine, Vanderbilt University, Nashville, TN 37232.
Carter
C E
CE
Hager
C
C
Kim
W J
WJ
Obermeier
S
S
Oeltmann
T N
TN
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D002236:Carbohydrate Conformation; D002845:Chromatography; D006596:Hexosaminidases / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007163:Immunosorbent Techniques; D007526:Isoelectric Point; D008358:Mannose / Q000032:analysis / Q000378:metabolism; D008361:Mannosidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D009844:Oligosaccharides / Q000032:analysis / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology*; D014357:Trypsin / Q000494:pharmacology; D043323:alpha-Mannosidase
D009844:Oligosaccharides; D000135:Acid Phosphatase; D006596:Hexosaminidases; D008361:Mannosidases; D043323:alpha-Mannosidase; D014357:Trypsin; D008358:Mannose