Koga M, Ohtsu M, Funatsu G
Gan. 1979 Oct;70(5):585-91.
The toxicity of lectins from castor bean (Ricinus communis L.), ricin-D, ricin-E, and castor bean hemagglutinin, was investigated on five cultured cell lines. The differential effect of their constituent polypeptide chains was also investigated using these cell lines. Ricin-D, ricin-E, and castor bean hemagglutinin (CBH) possessed cytoagglutinating activity and cytotoxic activity to all five cell lines. These lectins showed the strongest toxicity to L5178Y cells, which are leukemic cells. The toxic activity of ricin-D was stronger than that of CBH in all cell lines. The constituent polypebtide chains of ricin-D and CBH were separated by DEAE-cellulose chromatography and designated as isoleucine chain and alanine chain denoted by their N-terminal amino acids. Only alanine chain of ricin-D was toxic to cells grown in vitro, whereas isoleucine chain of ricin-D and alanine chain of CBH were not toxic to the cells. Moreover, it was found that both lectins caused syncytium formation in NIH3T3 cells infected with Moloney leukemia virus and this cell fusion activity was shown to be exclusively associated with the alanine chain. Cytotoxic, cell agglutinating, and syncytium forming effect of the lectins is due to binding of the alanine chain of ricin-D to galactose-like residues of the membrane constituents of these cells.
研究了蓖麻子（Ricinus communis L.）中的凝集素、蓖麻毒素-D、蓖麻毒素-E和蓖麻子血凝素对五种培养细胞系的毒性。还使用这些细胞系研究了它们组成多肽链的差异作用。蓖麻毒素-D、蓖麻毒素-E和蓖麻子血凝素（CBH）对所有五种细胞系均具有细胞凝集活性和细胞毒性活性。这些凝集素对白血病细胞L5178Y细胞表现出最强的毒性。在所有细胞系中，蓖麻毒素-D的毒性活性均强于CBH。通过DEAE-纤维素色谱法分离了蓖麻毒素-D和CBH的组成多肽链，并根据其N端氨基酸将其命名为异亮氨酸链和丙氨酸链。蓖麻毒素-D中只有丙氨酸链对体外培养的细胞有毒，而蓖麻毒素-D的异亮氨酸链和CBH的丙氨酸链对细胞无毒。此外，发现这两种凝集素在感染莫洛尼白血病病毒的NIH3T3细胞中均引起多核体形成，并且这种细胞融合活性仅与丙氨酸链有关。这些凝集素的细胞毒性、细胞凝集和多核体形成作用是由于蓖麻毒素-D的丙氨酸链与这些细胞的膜成分中的半乳糖样残基结合所致。
