CONFORMATIONAL CHANGES OF SOLUBLE QUANYLATE CYCLES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 可溶性鸟苷酸环化酶（sGC）是一种分子量为150 kD的异源二聚体蛋白，是细胞内主要的NO受体。NO结合血红素的N-末端结构域的？亚基，刺激cGMP的产生并导致NO依赖性信号级联。 由于我们不能使蛋白质结晶，结构测定受到了阻碍。 我们可以高产量地制备来自昆虫天蛾的缺少环化酶结构域的截短的sGC（msGC-NT 2，97 kD）。 该构建体的NO化学与全长蛋白质的相同。(Hu等人，J. Biol. Chem.，（2008），20968.）。分析性超离心（AUC）显示，当配体结合时，msGC-NT 2改变形状。SAXS研究将进一步确定我们的sGC构建体的低分辨率结构，并确定当配体结合时是否发生显著的结构域重排。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Soluble guanylate cyclase (sGC), a 150 kD heterodimeric protein, is the primary NO receptor in the cell. NO binds to heme in the N-terminal domain of the ? subunit, stimulates the production of cGMP and leads to NO-dependent signaling cascades. Structure determination has been hindered by our inability to crystallize the protein. We can prepare, in high yield, a truncated sGC (msGC-NT2, 97 kD) from the insect Manduca sexta that lacks the cyclase domain. The NO chemistry of this construct is identical to that of the full-length protein. (Hu, et.al., J. Biol. Chem., (2008), 20968.). Analytical ultracentrifugation (AUC) shows that msGC-NT2 changes shape when ligands bind. SAXS studies will further define the low resolution structure of our sGC construct and determine whether significant domain rearrangement occurs when ligands bind.