[Analysis of components of proteins from Echinococcus granulosus cyst fluid].

OBJECTIVE:To analyze the components of proteins from Echinococcus granulosus cyst fluid using the shotgun method, and to identify the active components with potential regulatory effects for immune dysregulation diseases. METHODS:The E. granulosus cyst fluid was collected aseptically from the hepatic cysts of patients with cystic echinococcosis, and characterized by liquid chromatography (LC) tandem mass spectrometry (MS/MS) following digestion with trypsin. The protein data were searched using the software MaxQuant version 1.6.1.0 and the cellular components, molecular functions, and biological processes of the identified proteins were analyzed using the Gene Ontology (GO) method. RESULTS:The E. granulosus cyst fluid separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) had a relative molecular mass of 25 to 70 kDa. LS-MS/MS analysis identified 37 proteins, including 32 known proteins and 5 unknown proteins. At least 4 proteins were preliminarily found to exhibit potential regulatory effects for immune dysregulation diseases, including antigen B, glutathione-S-transferase (GST), thioredoxin peroxidase (TPX) and malate dehydrogenase (MDH). GO enrichment analysis showed that the identified proteins had 149 molecular functions and were involved in 341 biological processes. CONCLUSIONS:E. granulosus cyst fluid has a variety of protein components, and four known proteins are preliminarily identified to be associated with immune dysregulation diseases.