摘要
利用Ｔｂ^（３＋）作为荧光探针研究天花粉蛋白（ＴＣＳ）的结构。Ｔｂ^（３＋）可置换天花粉蛋白中的Ｃａ^（２＋），发生从ＴＣＳ分子中的Ｔｒｐ残基到Ｔｂ^（３＋）的能量传递，使Ｔｒｐ的荧光发射强度减弱。利用光谱技术研究发现，Ｔｂ^（３＋）与ＴＣＳ亲和力小于Ｃａ（２＋）与ＴＣＳ的亲和力；Ｔｂ^（３＋）与其结合后基本不改变ＴＣＳ的构象，但Ｔｒｐ和Ｔｙｒ残基处的微环境发生变比；Ｃａ^（２＋）对ＴＣＳ构象有显著影响。
Tb3+ has been used as a fluorescent probe to study the structure of trichosanthin(TCS).The nonradioactive energy transfer from fluorescent active tryptophan(Trp)residue to the bound Tb3+ ions take place and the fluorescence of Trp is decreased when Tb3+ ions are bound to TCS to replace the Ca2+ in it.According to the results of Trp fluorescence and the information given from CD and UV absorption spectra,we have found that the affinity of Tb3+ to TCS is lower than that of Ca2+ ions to TCS. Significant change of TCS structure was not observed with the Tb3+ ions binding,The microenvironment surrounded Trp and Tyr may be changed slightly with the Tb3+ binding.The conformation of Ca2+ -free TCS was significantly changed compared with that of native TCS with the Trp residue moving into the interior of TCS molecules。 The Ca2+-binding site in TCS can be maintained partly when the Ca2+ is removed from TCS molecules.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1995年第12期1907-1910,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
吉林大学酶工程国家重点实验室和吉林大学分子光谱和分子结构开放实验室资助课题
关键词
天花粉蛋白
钙离子
铽离子
Tb￣(3+), Ca￣(2+), Trichosanthin, Fluorescent probe
