title: Modification of biological activities of Ricinus communis agglutinin by cross-linking with formaldehyde.
abstract: Formaldehyde treatment of Ricinus communis agglutinin, a nonmitogenic toxic 120 000 molecular weight (MW) lectin, yielded two distinct protein fractions: one was heterogeneous and contained high molecular weight lectin polymers (greater than 120 000), and the other was a homogeneous 120 000 MW protein. Both fractions lost their cytotoxicity after formaldehyde treatment and stimulated thymidine incorporation into lymphocytes. Binding of both treated lectin fractions to lymphocytes exhibited positive cooperativity, whereas binding of untreated lectin did not.
mesh_terms: D000328:Adult; D000372:Agglutination Tests; D000494:Allosteric Regulation; D002478:Cells, Cultured; D055598:Chemical Phenomena; D002621:Chemistry; D003432:Cross-Linking Reagents; D004912:Erythrocytes / Q000187:drug effects; D005557:Formaldehyde; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D008934:Mitogens; D037121:Plant Lectins; D013329:Structure-Activity Relationship; D013936:Thymidine / Q000378:metabolism
chemical_list: D003432:Cross-Linking Reagents; D037102:Lectins; D008934:Mitogens; D037121:Plant Lectins; C017707:Ricinus communis agglutinin-1; D005557:Formaldehyde; D013936:Thymidine