Abstract
The tissue-specific, cell-aggregating component of embryonic neural retina cells was purified from the retina cell-aggregating factor and characterized as a glycoprotein. Its molecular weight in solution is in the range of 50,000, and it contains 10-15% carbohydrate. The amino-acid and carbohydrate compositions have been determined. The glycoprotein is produced by embryonic neural retina cells in primary monolayered cultures and is released into the medium. Its tissue-specific, cell-aggregating effect requires integrity of the polypeptide portion, but not of the carbohydrate portion. We suggest that the isolated molecule is a specific determinant of the embryonic retina cell-surface and that it is involved in mediating self-recognition and selective adhesiveness of these cells.