解开三维蛋白晶体结构的秘密

　　

生物通报道，来自加州理工大学和加州大学圣地亚哥分校的研究者联合研究蛋白晶体结构，构建了一个蛋白三维结构数学模型，破解了氨基酸链变蛋白三维结构的秘密。

 

研究人员使用加州理工大学研发的新技术获得大量的实验数据构建了一个蛋白折叠结构模型。

 

研究者使用一个能捕捉到皮秒图像的摄影机来观察蛋白结构；链接蛋白与摄影机的是一个探针，这个探针可捕捉激光的脉冲波激发出的荧光，并将这一信息传递到模型的探针上。这些发光的信息能将链接蛋白的结构秘密转移到模型上，这样就可勾勒出蛋白的三维立体结构。

 

The UCSD model of the folding energy landscape for cytochrome c. The landscape was probed experimentally at Caltech, using time-resolved fluorescence energy transfer from six donor labels (represented as single spheres of differing colors) to the heme acceptor. (Credit: Peter Weinkam, UCSD)

 

 Electrostatic effects on funneled landscapes and structural diversity in denatured protein ensembles.

【Abstract】

The denatured state of proteins is heterogeneous and susceptible to general hydrophobic and electrostatic forces, but to what extent does the funneled nature of protein energy landscapes play a role in the unfolded ensemble? We simulate the denatured ensemble of cytochrome c using a series of models. The models pinpoint the efficacy of incorporating energetic funnels toward the native state in contrast with models having no native structure-seeking tendency. These models also contain varying strengths of electrostatic effects and hydrophobic collapse. The simulations based on these models are compared with experimental distributions for the distances between a fluorescent donor and the heme acceptor that were extracted from time-resolved fluorescence energy transfer experiments on cytochrome c. Comparing simulations to detailed experimental data on several labeling sites allows us to quantify the dominant forces in denatured protein ensembles.