Trypanosoma cruzi serinecarboxipeptidase is a sulfated glycoprotein and a minor antigen in human Chagas disease infection

AbstractIn this work, the presence of sulfatedN-glycans was studied in a high-mannose-type glycoprotein ofTrypanosoma cruzi with serinecarboxipeptidase (TcSCP) activity. The immune cross-reactivity between purified SCP and Cruzipain (Cz) was evidenced using rabbit sera specific for both glycoproteins. Taking advantage that SCP co-purifies with Cz from Concanavalin-A affinity columns, the Cz –SCP mixture was desulfated, ascribing the cross-reactivity to the presence of sulfate groups in both molecules. Therefore, knowing that Cz is a sulfated glycoprotein, with antigenic sulfated epitopes (sulfotopes), SCP was excised from SDS-PAGE and theN-glycosydic chains were analyzed by UV –MALDI–TOF-MS, confirming the presence of short-sulfated high-mannose-type oligosaccharidic chains. Besides, the presence of sulfotopes was analyzed in lysates of the different parasite stages demonstrating that a band with apparent molecular weight similar to SCP was highly recognized in trypom astigotes. In addition, SCP was confronted with sera of infected people with different degrees of cardiac dysfunction. Although most sera recognized it in different groups, no statistical association was found between sera antibodies specific for SCP and the severity of the disease. In summary, our findings demonstrate (1) the presence of sulfate groups in theN-glycosidic short chains of nativeTcSCP, (2) the existence of immune cross-reactivity between Cz and SCP, purified from epimastigotes, (3) the prese...
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research