Terbium(Ⅲ)as fluorescence probe in the study of the interaction of rare earth and transition metal ions with concanavalin A  

作　　者：YANG Pin MA Gui-Bin YANG Bin-Sheng Institute of Molecular Science,Shanxi University,Taiyuan 

出　　处：《Acta Chimica Sinica English Edition》1989年第5期443-449,共1页

摘　　要：The binding site for calcium(Ⅱ)on concanavalin A(con-A)can be occupied by rare earth ions.When terbium(Ⅲ)ion binds to con-A,its fluorescence intensity is tremendously enhanced because of an energy transfer from one or more tryptophan residues in close proximity to the bound terbium(Ⅲ).The dissociation constant of the con-A-Tb(Ⅲ)complex is 8.90×10^(-6)M,obtained from terbium(Ⅲ)fluorescence titration with con-A.The dissociation constant of the complexes of con-A with other rare earth and transition metal ions was obtained through their competition with terbium(Ⅲ)in the reaction with con-A,i.e.the quenching of con-A enhanced fluorescence.The results indicate that the binding of rare earth ions with con-A is dependent not only on their ionic radius but also on the hard-soft acid-base strength of the metal ions.The binding site for calcium(Ⅱ)on concanavalin A(con-A)can be occupied by rare earth ions.When terbium(Ⅲ)ion binds to con-A,its fluorescence intensity is tremendously enhanced because of an energy transfer from one or more tryptophan residues in close proximity to the bound terbium(Ⅲ).The dissociation constant of the con-A-Tb(Ⅲ)complex is 8.90×10^(-6)M,obtained from terbium(Ⅲ)fluorescence titration with con-A.The dissociation constant of the complexes of con-A with other rare earth and transition metal ions was obtained through their competition with terbium(Ⅲ)in the reaction with con-A,i.e.the quenching of con-A enhanced fluorescence.The results indicate that the binding of rare earth ions with con-A is dependent not only on their ionic radius but also on the hard-soft acid-base strength of the metal ions.

分 类 号：O6[理学—化学]