Purification of a putative lipoprotein receptor from Schistosoma japonicum adult worms.

A 43-kDa putative lipoprotein receptor from Schistosoma japonicum adult worms (Sj43) has been purified by reverse-phase high-performance liquid chromatography (HPLC) using a Waters Delta-pak C4 300 A 15 mu 3.9 mm x 300 mm column. A linear acetonitrile gradient from 10-95%, spanning 40 min and at a flow rate of 0.9 ml min-1 was employed for the elution of bound material. Sj43 had a retention time of approximately 13 min on the column, whereas other main components from the parasite extract had a much longer retention time. Sj43 purified as a doublet which could be cleaved with Staphylococcus aureus V8 protease but was unaffected by treatment with a mixture of endoglycosidase F and glycopeptidase F. Human low-density lipoprotein exhibited typical saturation kinetics on the HPLC-purified Sj43 with a calculated stoichiometry of 2 mol LDL mol-1 of the putative receptor. No evidence of high-density lipoprotein (HDL3) saturation was observed on purified Sj43, this being of some interest since it parallels observations made with mammalian HDL3-binding proteins.