Raghunathan V, Mowery P, Rozycki M, Lindberg U, Schutt C
Frick Chemical Laboratory, Princeton University, NJ 08544.
FEBS Lett. 1992 Feb 3;297(1-2):46-50. doi: 10.1016/0014-5793(92)80324-a.
The effect on the structure of profilin of phosphatidylinositol 4,5-bisphosphate (PIP2) binding was probed by fluorescence and circular dichroism (CD) spectroscopy. Fluorescence of Trp3 and Trp31 of profilin at 292 nm showed a linear decrease in solution emission at 340 nm as PIP2/profilin was increased from 0 to 80:1, apparently due to a static quenching mechanism involving formation of a nonfluorescent PIP2/profilin complex. CD spectra revealed an increase of up to 3.3-fold in the molar ellpticity at 222 nm for profilin as it binds PIP2, as well as changes in the Cotton effect between 250 and 310 nm. These results are consistent with a possible increase in the alpha-helix content of profilin triggered by the binding of PIP2.
通过荧光和圆二色性（CD）光谱法研究了磷脂酰肌醇4,5 - 二磷酸（PIP2）结合对肌动蛋白单体结合蛋白结构的影响。当PIP2/肌动蛋白单体结合蛋白的比例从0增加到80:1时，肌动蛋白单体结合蛋白中色氨酸3（Trp3）和色氨酸31（Trp31）在292nm处的荧光显示溶液在340nm处的发射呈线性下降，这显然是由于涉及形成非荧光PIP2/肌动蛋白单体结合蛋白复合物的静态猝灭机制。CD光谱显示，肌动蛋白单体结合蛋白在结合PIP2时，在222nm处的摩尔椭圆率增加了3.3倍，同时在250至310nm之间的科顿效应也发生了变化。这些结果与PIP2结合引发的肌动蛋白单体结合蛋白α-螺旋含量可能增加一致。
