A new method for concentration of proteins in the calcareous corpuscles separated from the spargana of Spirometra erinacei

Abstract

Calcareous corpuscles are a characteristic structure found in larval and adult stage cestodes. These cor-puscles are known to contain several protein components and to possess protein-binding activity. However, the pro-teins bound to calcareous corpuscles in situ have not been studied. The present study was undertaken to identify theproteins on calcareous corpuscles. Calcareous corpuscles were purified from the plerocercoids (= spargana) ofSpirometra erinacei, and serially dissolved using 0.1 M sulfamic acid solution. Collected supernatants were examinedby sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining. The results showedthat only the fraction remaining after the 19th dissolved fraction contained proteins. A total of 20 protein moleculeswere detected in gel, with major bands at 56, 53, 46, 40, 35, 29, 28, 24.5, 21, 19, 16, 13, 10 and 8 kDa. In particular,the proteins corresponding to the 21 and 16 kDa bands were most abundant. Our results demonstrated for the firsttime the protein contents of the calcareous corpuscles of spargana. Further studies on the functions of these proteins are required.