The presence in Trypanosoma cruzi microsomes of alpha(1,2), alpha(1,3) and alpha(1,6) mannosidase activities not involved in protein-linked Man9GlcNAc2 processing.
Trypanosoma cruzi microsomes were found to possess membrane-bound alpha(1,2), alpha(1,3) and alpha(1,6) mannosidase activities that had an almost neutral optimum pH value, did not require CaCl2 for activity and were inhibited by swainsonine but not by deoxymannojirimycin. A mannosidase activity that degraded p-nitrophenylmannoside and that was inhibited by swainsonine was also present in the parasite microsomes. Experiments performed with intact cells showed that processing of protein-linked Man9GlcNAc2 was inhibited by deoxymannojirimycin but not by swainsonine. It was concluded that the activities detected were not involved in protein-linked Man9GlcNAc2 processing.
Instituto de Investigaciones Bioquímicas Fundación Campomar, Buenos Aires, Argentina.
M T
MT
Xavier
S
S
Merello
A J
AJ
Parodi
D000818:Animals; D006863:Hydrogen-Ion Concentration; D008361:Mannosidases / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008861:Microsomes / Q000201:enzymology; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D013379:Substrate Specificity; D017026:Swainsonine / Q000494:pharmacology; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000378:metabolism
D008562:Membrane Glycoproteins; C025363:mannoproteins; D008361:Mannosidases; C078166:alpha(1-6)mannosidase; C046090:mannosyl-oligosaccharide 1,2-alpha-mannosidase; D017026:Swainsonine