title: The interaction of human serum with the surface membrane of schistosomula of Schistosoma mansoni.
abstract: After contact with human serum, a series of proteins become exposed on the surface membranes of schistosomula of Schistosoma mansoni as revealed by radioiodination of the intact parasites. Among the proteins, a doublet (Mr 45 000) is particularly prominent. These doublet proteins, which are believed to be parasite-derived, become apparent after a very short time of incubation with human serum (10 min or less) and are expressed on the surface membranes after contact with a high molecular weight component of human serum (Mr greater than 80 000). Pretreatment of the parasites with 1.25 mM colchicine or fixation with 2% glutaraldehyde does not prevent the serum-induced expression of the doublet proteins. Extraction of the parasites with chloroform:methanol 2:1 (v/v), however, blocks the human serum effect. Affinity chromatography using immobilized low density lipoproteins (LDL) from human serum shows a tight binding between the 125I-labelled 45 kDa doublet to the LDL. The possible role of the 45 kDa doublet as a receptor for LDL is discussed.
mesh_terms: D000818:Animals; D001790:Blood Physiological Phenomena; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D008970:Molecular Weight; D011973:Receptors, LDL / Q000378:metabolism; D012550:Schistosoma mansoni / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D011973:Receptors, LDL