The presence of complex-type oligosaccharides at the C-terminal domain glycosylation site of some molecules of cruzipain

ARMANDO J. PARODI *, CARLOS LABRIOLA, JUAN J. CAZZULO

MOLECULAR AND BIOCHEMICAL PARASITOLOGY

ELSEVIER SCIENCE BV

Lugar: Netherlands; Año: 1995 vol. 69 p. 247 - 255

0166-6851

AbstractCruzipain is a lysosomal enzyme of the flagellate Trypanosoma cruzi. It has three potential asparagine-glycosylationsites, two in the catalytic domain and one in the C-terminal domain. The latter appeared to have both high mannose- andcomplex-type oligosaccharides, whereas the catalytic domain only had compounds of the former type. The partialsusceptibility of the complex-type compounds to endo+W-acetylglucosaminidase H and their relative mannose andgalactose content indicate that they had hybrid/monoantennary and biantennary structures. The same pattern of highmannose-type compounds was found at both domains, thus indicating that in cruzipain molecules having only highmannose-type compounds, all oligosaccharides were equally exposed to processing glycosidases and glycosyltransferases.As heterogenity of the protein C-terminal domain has already been detected, it is suggested that this feature might elicit anincreased accessibility to processing enzymes responsible for complex-type oligosaccharide formation in certain cruzipainmolecules or, alternatively, that a second glycosylation site with increased accessibility might be present in certain cruzipainmolecules. Furthermore, the presence of complex-type oligosaccharides strongly suggests that, as in mammalian cells, T.cruzi lysosomal enzymes traverse the entire Golgi apparatus up to the trans-Golgi cisternae and the trans-Golgi networkbefore reaching lysosomes.