SMALL ANGLE SCATTERING STUDIES OF CAMP & CGMP DEPENDENT PROTEIN KINASES

Ia型cGMP依赖性蛋白的小角散射数据 用cGMP（1至13摩尔当量）滴定的PKG显示 cGMP结合诱导的大的构象变化。 PKG是二聚体 在每个单体组分内具有调节和催化结构域。 每个单体上有一个“慢”和一个“快”cGMP结合位点。 散射数据的P（r）分析表明， 构象变化涉及分子质量远离 分子的中心，可能是由于分子的运动， 调控域远离催化域。 的半径 PKG的回旋从45.4 E急剧增加30%到59.4 E， 添加cGMP。 似乎每个PKG的4个cGMP结合位点 可能只需要部分饱和就可以看到完整的构象 变化 进一步的研究正在进行中，以确定 慢和快cGMP结合位点。

Small-angle scattering data from type Ia cGMP-dependent protein kinase (PKG) titrated with cGMP (1 through 13 molar equivalents) shows a large conformational change induced by cGMP-binding. PKG is a dimer with a regulatory and catalytic domain within each monomer component. There is one 'slow' and one 'fast' cGMP binding site on each monomer. A P(r) analysis of the scattering data indicates that the conformational change involves a shift of the molecular mass away from the center of the molecule, possibly due to the movement of the regulatory domain away from the catalytic domain. The radius of gyration of PKG increases dramatically by 30% from 45.4 to 59.4 E upon addition of cGMP. It appears that the 4 cGMP binding sites per PKG may only need to be partially saturated to see the full confromational change. Further study is underway to characterize the exact role of the slow and fast cGMP-binding sites.