The promastigote surface protease (gp63) of Leishmania is expressed but differentially processed and localized in the amastigote stage

• Published in: Molecular and biochemical parasitology Vol. 37; no. 2; p. 263
• Main Authors: Medina-Acosta, E, Karess, R E, Schwartz, H, Russell, D G
• Format: Journal Article
• Language: English
• Published: Netherlands 01-12-1989
• Subjects: Animals; Electrophoresis, Gel, Two-Dimensional; Fluorescent Antibody Technique; Immunohistochemistry; Leishmania mexicana - enzymology; Leishmania mexicana - growth & development; Membrane Glycoproteins - analysis; Membrane Glycoproteins - biosynthesis; Membrane Glycoproteins - metabolism; Metalloendopeptidases; Peptide Mapping; Phosphatidylinositols - analysis; Precipitin Tests; Protein Processing, Post-Translational; Protozoan Proteins - analysis; Protozoan Proteins - biosynthesis; Protozoan Proteins - metabolism
• ISSN: 0166-6851
• DOI: 10.1016/0166-6851(89)90158-8

The expression, processing and localization of the promastigote surface glycoprotein, gp63, in the amastigote form of Leishmania mexicana was examined. Metabolically labeled protein was immunoprecipitated from promastigotes and amastigotes. The isolated proteins were subjected to deglycosylation and partial peptide mapping. The cleavage products generated migrated similarly in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the proteins were closely related. The majority of gp63 in amastigotes was inaccessible to surface-labeling procedures, and lacked the phosphatidylinositol membrane anchor. Immunolocalization of this subpopulation of gp63 revealed it to be present within the parasite's flagellar pocket. Despite the relative paucity of 'membrane-form' gp63, isolation and analysis of surface proteins from lesion amastigotes indicated that gp63 was the most abundant protein on the amastigote surface.