Avigliano L, Aducci P, Sirianni P, Finazzi-Agrò A
Int J Biochem. 1984;16(12):1409-13. doi: 10.1016/0020-711x(84)90249-0.
The binding of Tb3+ and other lanthanides to Con A has been studied by sensitized Tb3+ luminescence, by quenching of intrinsic fluorescence and by activity measurements. In all the experimental conditions tested, it was found that holo and apo Con A bind lanthanide ions at a site different from the binding sites of the constitutive metals, Mn2+ and Ca2+. The bound lanthanide did not affect the saccharide binding ability and the hemoagglutinating ability of Con A. The intrinsic fluorescence of Con A is quenched by the binding of Tb3+ and Gd3+. The same quenching is obtained by shifting the pH of Con A from pH 6.5 to 4.5. It is proposed that H+ and Ln3+ completely quench a tryptophan, perhaps the residue 88 or 182.
通过敏化Tb3+发光、固有荧光猝灭和活性测量等方法，研究了Tb3+和其他镧系元素与伴刀豆球蛋白A（Con A）的结合情况。在所有测试的实验条件下，发现全酶和脱辅基Con A在与组成性金属Mn2+和Ca2+的结合位点不同的位点结合镧系离子。结合的镧系元素不影响Con A的糖类结合能力和血凝能力。Con A的固有荧光通过Tb3+和Gd3+的结合而猝灭。将Con A的pH从6.5调节到4.5也可获得相同的猝灭效果。有人提出，H+和Ln3+完全猝灭了一个色氨酸，可能是第88位或第182位残基。
