The effect of chemical modification on Polygonatum cyrtonema Hua.lectin Ⅱ(PCLⅡ)was investigated in order to elucide the role of tyrosine in the bioactivity of PCL Ⅱ.Modification of tyrosine in PCL Ⅱ with p nitrobe...The effect of chemical modification on Polygonatum cyrtonema Hua.lectin Ⅱ(PCLⅡ)was investigated in order to elucide the role of tyrosine in the bioactivity of PCL Ⅱ.Modification of tyrosine in PCL Ⅱ with p nitrobenzene sulfonyl fluoride (NBSF) led to a loss of 40% of the mitogenic activity towards T\|cell,but had no effect on hemagglutination.The hemagglutination of PCL Ⅱ also kept no change when modified by 10 mmol/L NAI,while it decreased slightly in 20 mmol/L NAI,which indicated that amino group played marginal role in the binding site,since the thiol group was not essential for the hemagglutination.Modification of PCL Ⅱ with 5 and 10 mmol/L NAI was accompanied by a loss of 30% and 48% of mitogenic activity respectively.When deacetylation by hydroxylamine,PCL Ⅱ almost regained all activity towards T cell,indicating that phenolic hydroxyl group on tyrosine was essential for the mitogenic activity and amino group or thiol group also played marginal role in the course.展开更多
文摘The effect of chemical modification on Polygonatum cyrtonema Hua.lectin Ⅱ(PCLⅡ)was investigated in order to elucide the role of tyrosine in the bioactivity of PCL Ⅱ.Modification of tyrosine in PCL Ⅱ with p nitrobenzene sulfonyl fluoride (NBSF) led to a loss of 40% of the mitogenic activity towards T\|cell,but had no effect on hemagglutination.The hemagglutination of PCL Ⅱ also kept no change when modified by 10 mmol/L NAI,while it decreased slightly in 20 mmol/L NAI,which indicated that amino group played marginal role in the binding site,since the thiol group was not essential for the hemagglutination.Modification of PCL Ⅱ with 5 and 10 mmol/L NAI was accompanied by a loss of 30% and 48% of mitogenic activity respectively.When deacetylation by hydroxylamine,PCL Ⅱ almost regained all activity towards T cell,indicating that phenolic hydroxyl group on tyrosine was essential for the mitogenic activity and amino group or thiol group also played marginal role in the course.
