Yoshihiko Murata

A monoclonal antibody against a glycolipid SEGLx from Spirometra erinaceieuropaei plerocercoid

A mouse monoclonal antibody AK97 (IgM) was established against a new type of glycosphingolipid, SEGLx, isolated from plerocercoids of tapeworm, Spirometra erinaceieuropaei. The chemical structure of SEGLx (Gal beta1-4(Fuc alpha1-3)(Glc beta1-3Gal beta1-ceramide) had been previously characterized. The specificity of AK97 was determined by thin-layer chromatography-immunostaining and enzyme-linked immunosorbent assay. AK97 was found to be directed to SEGLx and GalSEGLx (Gal beta1-4(Fuc alpha1-3)Glc beta1-3(Gal beta1-6)Gal beta1-ceramide) and also showed cross-reactivity with the stage specific embryonic antigen-1 (SSEA-1), the epitope being defined to be the non-reducing terminal trisaccharide sequence. On immunohistochemical examination, AK97 predominantly stained the tegument, the external surfaces of worms which have a brush border-like organization. Based on the immunohistochemical findings for the staining liability as to organic solvents and the results of Western blot analysis of the plerocercoid glycoproteins, it was proved that the antigens in the tapeworm were glycolipids. Considering that the tapeworm is in direct contact with its hosts tissue through the tegument, the membrane surface of which is exposed to the external environment, it is suspected that SEGLx and GalSEGLx on the tegument play functionally important roles in the host parasite interaction.

Monohexosylceramides of larval and adult forms of the tapeworm,spirometra erinacei

The occurrence of glycosphingolipids with unique carbohydrate structures in different species of cestode, Platyhelminth, which had been shown, previously, prompted us to study the molecular species of the monohexosylceramides (cerebrosides) in the pseudophyllidean cestode,Spirometra erinacei. The purpose of the study was to obtain a basis for future investigations of the physiological role of glycolipids in parasitism. Cerebrosides were isolated froms. erinacei at two growth stages, i.e., from the larval form (plerocercoid) and from the adult tapeworms (intestinal form). The cerebrosides were separated into four subfractions by silica gel column chromatography, and their constituents were analyzed by gasliquid chromatography, gas chromatography/mass spectrometry, and high-performance liquid chromatography/mass spectrometry. The hexoses of the cerebrosides consisted primarily of galactose in both growth stages, while only a small amount of glucose was detected. The ceramides were composed of sphinganine (d18∶0) and phytosphingosine (t18∶0) as sphingoid bases, and of nonhydroxy fatty acids ranging from C16 to C30 and hydroxy stearic acid (18h∶0). The cerebrosides of adult tapeworms contained more 18h∶0 than those of plerocercoids. The combination of hexoses and ceramides in the cerebroside molecules was slightly different in the two growth stages: the glucocerebrosides of plerocercoids contained only d18∶0-nonhydroxy fatty acids in their ceramide moieties, whereas those of adult tapeworms contained varying ceramide moieties. Our data indicate that the molecular species of glycolipids present were essentially homeostatic throughout growth in spite of the entirely different environmental conditions, although there were slight differences in the hexose distribution in the two growth stages.

S19.19 Glycosphingolipids of plerocercoids of parasite,Spirometra erinacei

S19.17 Unusual Structures of Gangliosides from Starfishes G. P. Smirnova and N. V. Chekareva N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia. Gangliosides containing unusual oligiosaccharide chains were isolated from starfish Asterias rathbuni and Leptychaster anomalus belonging to different orders. Their structures were elucidated by chemical and physico-chemical methods. The main ganglioside from A. rathbuni was found to contain pentasaccharide chain with two 8-O-methyl-N-glycolylneuraminic acid residues bound to one N-acetylgalactosamine residue in positions 3 and 6:8-O-Me-NeuGca2-3 (8-O-MeNeuGca2-6)GalNAc/31-3Galfll-4Glcpl-lCer. The ganglioside from L. anomalus contained tetrasaccharide chain where Nglycolylneuraminic acid residue accupied the subterminal position and is glyeosylated at 0-4 by the terminal galactopyranose residue: Gal/31-4NeuGc2-3Gal/31-4Glcpl-lCer. The lipid moieties of both gangliosides were shown to contain normal and a-hydroxy fatty acids at a ratio of about 1:1. Sphingosines were detected in the L. anomalus ganglioside, whereas approximately equal amounts of sphingosines and phytosphingosines were found in the A. rathbuni ganglioside. Quantitative analysis of long-chain bases and fatty acids was carried out.