Popis: |
An electrophoretically homogenous lectin was obtained from rice germ by extraction with acidified saline, precipitation with ammonium sulfate, and affinity adsorption on chitin. The molecular weight of the lectin was ascertained by gel filtration on Sephadex G-75 to be 23 000. Sodium dodecyl sulfate – polyacrylamide electrophoresis with 1% mercaptoethanol gave three bands, with molecular weights of 11 300, 13 700 and 19 000, indicating disulfide cleavage to form subunits. The intact lectin was found to have (i) cell agglutinating activity on erythrocytes and lymphocytes, sperm cells, sweet potato mesophyll cells, and callus cells of rice, all specifically inhibited by N-acetylglucosamine and (ii) mitogenic activity when tested on human peripheral lymphocytes and mouse spleen lymphocytes. The amino acid composition, N-terminal residues glycine and lysine, and isoelectric point (pH 6.5–6.8) of the lectin were determined. |