Homogenates of Diplostomum pseudospathaceum cercariae agglutinated mouse erythrocytes. The haemagglutination could be inhibited by certain glycoconjugates containing beta-1,3- and beta-1,4-glycan chains and also by some simple saccharides. The most potent inhibitors were heparin and some other glycosaminoglycans, bacterial lipopolysaccharides, laminarin (a beta-1,3-glucan) and lactulose. After electrophoresis of cercarial proteins, a dominant double band appeared in the 22-24 kDa region of gels. On blots, this protein bound labelled laminarin and it was also one of the few proteins recognised by mouse antibodies raised against cercarial haemagglutinins. In addition, mouse polyclonal antibodies against the beta-1,3-glucan-binding protein bound exclusively to the 22-24 kDa region on Western blots. Histochemistry revealed strong binding of labelled laminarin to cercarial penetration glands; this reaction was fully blocked by unlabelled laminarin. Other labelled glycoconjugates such as heparin, hyaluronic acid and a bacterial lipopolysaccharide also bound to the glands. Immunohistochemistry confirmed the localisation of the beta-1,3-glucan-binding protein in penetration glands. Reaction of the cercarial protein with immunoglobulins from non-immunised mice was observed on both nitrocellulose membranes and histological sections; this could be blocked by laminarin in incubation buffers. We consider the cercarial haemagglutinin to be a lectin which is identical with the 22-24 kDa beta-1,3-glucan-binding protein. According to the binding specificity and localisation we speculate on a role of this lectin in cercarial penetration into the host, probably as a tissue recognition or antibody rendering factor.

• MeSH
• erytrocyty fyziologie   MeSH
• hemaglutinace * MeSH
• hemaglutinační testy MeSH
• hemaglutininy analýza   metabolismus   MeSH
• králíci MeSH
• krysa rodu Rattus MeSH
• lektiny analýza   metabolismus   MeSH
• lidé MeSH
• Lymnaea parazitologie   MeSH
• myši inbrední BALB C MeSH
• myši inbrední CBA MeSH
• myši MeSH
• proteiny červů analýza   metabolismus   MeSH
• protilátky helmintové biosyntéza   MeSH
• psi MeSH
• testy inhibice hemaglutinace MeSH
• transportní proteiny metabolismus   MeSH
• Trematoda růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• myši MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• glucan-binding proteins MeSH Prohlížeč
• hemaglutininy MeSH
• lektiny MeSH
• proteiny červů MeSH
• protilátky helmintové MeSH
• transportní proteiny MeSH

A beta-1,3-glucan-binding lectin from the penetration glands of Diplostomum pseudospathaceum cercariae was isolated by affinity chromatography using yeast glucan and curdlan as affinity matrices. Further purification to homogeneity was performed by cation-exchange chromatography. The protein migrated as a double band around 24 kDa in gels after SDS-PAGE. The protein is of strongly basic nature--its pI shown by native IEF was around 10. The mass of the protein determined by MALDI-TOF mass spectrometry was 23.9 kDa. N-terminal sequence as well as some internal sequences showed significant alignments with several cysteine protease sequences found in databases. The protein bound a biotinylated synthetic analogue of the irreversible inhibitor of cysteine proteases, E-64 and, moreover, its proteolytic activity was demonstrated in substrate gels. The enzymatic activity could be inhibited by the cysteine protease inhibitor E-64; therefore, the investigated protein was considered to be a bifunctional molecule possessing both lectin and enzyme activities. Glycanohydrolytic activity was not proved. The detected characters of this molecule lead to a hypothesis on its role in penetration of Diplostomum cercariae into fish hosts--that of binding to the carbohydrates of fish mucus and concurrent cleaving of protein components of the mucus and skin.

• MeSH
• chromatografie afinitní MeSH
• chromatografie iontoměničová MeSH
• cysteinové endopeptidasy izolace a purifikace   metabolismus   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• exokrinní žlázy cytologie   enzymologie   metabolismus   MeSH
• hlemýždi parazitologie   MeSH
• isoelektrická fokusace MeSH
• molekulární sekvence - údaje MeSH
• receptory buněčného povrchu * MeSH
• sekvence aminokyselin MeSH
• sekvence nukleotidů MeSH
• sekvenční seřazení MeSH
• transportní proteiny chemie   izolace a purifikace   metabolismus   MeSH
• Trematoda chemie   enzymologie   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cysteinové endopeptidasy MeSH
• receptory buněčného povrchu * MeSH
• saccharide-binding proteins MeSH Prohlížeč
• transportní proteiny MeSH