Pcl ii had two mutations in nueleotide sequences and amino acid sequence compared with that of natural pcl ii . the effect of chemical modification of amino acid residues upon haemagglutination and mitogenic activity toward t - lymphocytes was investigated . modification of tyrosine ( 1 - acetylimidazole and 4 - nitrobenzenesulphonyl fluoride ) did not alter haemagglutination but decreased mitogenic activity by about one half 采用不同的方法对酪氨酸( tyr )进行了修饰:用勺r酚经基专一性试剂对硝基苯磺酞氟( nbsf )修饰pcln ，导致pcln促淋巴细胞有丝分裂活性大幅下降，表明巧r的酚经基对于此活性是必需的。
