The identification, purification, and characterization of two invariant surface glycoproteins located beneath the surface coat barrier of bloodstream forms of Trypanosoma brucei.

摘要: Two new polypeptides, termed ISG70 and ISG64, have been found in Trypanosoma brucei, using enzyme-catalyzed radioiodination techniques. Both are externally disposed integral membrane glycoproteins, containing N-linked carbohydrate chains. No structural homology was detected between ISG70, or the variant surface glycoprotein (VSG) when assessed by 1) comparative peptide mapping, 2) immunoprecipitation analysis, 3) lectin affinity chromatography. occurred 5.1 x 10(4) copies/cell has purified 880-fold from detergent extracts of plasma membranes a procedure that includes gel filtration, chromatography, preparative SDS-polyacrylamide electrophoresis. present only bloodstream forms specifically six different cloned variants Molteno Institute trypanosomal antigen type (MITat) serodeme T. brucei single International Laboratory for Research on Animal Diseases (ILTat) examined. Rabbits with chronic infections displayed circulating antibodies against ISG70. immunogenicity its invariant nature suggest it may be useful development an effective serodiagnostic test. Furthermore, stage-specific location combined implies function is strictly related to physiological role required parasite's residence mammalian host.