[Preparation and application of monoclonal antibodies against sialoglycoprotein purified from human submandibular-sublingual saliva].

Sialoglycoprotein (SGP) having relatively high molecular weight was purified from human submandibular sublingual saliva by anion exchange chromatography on Q-Sepharose Fast Flow followed by gel filtration on Superose 6 prep grade. The molecular weight of SGP was estimated to be about 440,000 and the isoelectric points obtained by IEF-PAGE, ranged from 5.2 to 5.8. The purified SGP contained high compositions of glutamic acid, proline, glycine and aspartic acid which were calculated as about 57% of the total amino acids, and about 15% of sugars such as N-acetylneuraminic acid, galactose, fucose, mannose, N-acetylgalactosamine and N-acetylglucosamine. A panel of 23 murine monoclonal antibodies (MAbs; 8 IgG1, 15 IgM) directed against SGP was prepared. Although three protein components were detected by SDS PAGE, SGP specific MAb reacted intensely with a 60 kilodalton of protein component. Bacteroides gingivalis 381 showed high binding ability to SGP, but this interaction was inhibited by SGP specific MAb. To detect SGP in the pellicle formed on fragments of human dental enamel, SGP specific MAb were used. During the first hour of formation, rapid increase of SGP detected was observed, and it remained relatively unchanged between 1 and 24 h after beginning of pellicle formation. This work has suggested that SGP purified from submandibular-sublingual saliva is a main component of salivary pellicle on tooth surface and plays an important role in the interaction with oral bacteria including Bacteroides gingivalis.