Abstract
Sugar moieties of glycoproteins in silkworm hemolymph were examined with fluorescein isothiocyanate (FITC)-labeled lectins. The glycoproteins were separated by polyacrylamide gel electrophoresis (PAGE) and transferred to a hydrophobic polyvinylidene difluoride membrane. The membranes were treated with several kinds of FITC-labeled lectins. A glycoprotein of 130 kDa molecular weight was the principal glycoprotein on the electrophoretogram and was found to react well with lectins from Canavalia ensiformis, Lens culinaris and Pisam sativum. The silkworm hemolymph proteins including the 130k-glycoprotein did not react with lectins from Triticum vulgaris, Limulus polyphemus and Vicia villosa, while the control substances, sheep blood proteins and fetuin, a plasma glycoprotein from calf serum, reacted with the lectin from T. vulgaris. These findings indicate that the main terminal residue of the sugar side chains of the 130k-glycoprotein in the silkworm hemolymph is not N-acetyl neuraminic acid (NANA) or N-acetyl glucosamine but mannose or glucose or N-acetyl galactosamine.
