Ozhogina Olga A, Grishaev Alexander, Bominaar Emile L, Patthy László, Trexler Maria, Llinás Miguel
Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Biochemistry. 2008 Nov 25;47(47):12290-8. doi: 10.1021/bi800555z.
Neurotrypsin is a multidomain protein that serves as a brain-specific serine protease. Here we report the NMR structure of its kringle domain, NT/K. The data analysis was performed with the BACUS (Bayesian analysis of coupled unassigned spins) algorithm. This study presents the first application of BACUS to the structure determination of a 13C unenriched protein for which no prior experimental 3D structure was available. NT/K adopts the kringle fold, consisting of an antiparallel beta-sheet bridged by an overlapping pair of disulfides. The structure reveals the presence of a surface-exposed left-handed polyproline II helix that is closely packed to the core beta-structure. This feature distinguishes NT/K from other members of the kringle fold and points toward a novel functional role for a kringle domain. Functional divergence among kringle domains is discussed on the basis of their surface and electrostatic characteristics.
神经胰蛋白酶是一种多结构域蛋白,作为一种脑特异性丝氨酸蛋白酶。在此,我们报道了其kringle结构域NT/K的核磁共振结构。数据分析采用BACUS(耦合未分配自旋的贝叶斯分析)算法进行。本研究首次将BACUS应用于无先前实验三维结构的未富集13C蛋白的结构测定。NT/K采用kringle折叠结构,由一对重叠的二硫键桥接的反平行β-折叠组成。该结构揭示了一个暴露于表面的左手多聚脯氨酸II螺旋的存在,该螺旋紧密堆积在核心β-结构上。这一特征使NT/K与kringle折叠的其他成员区分开来,并指向kringle结构域的一种新功能作用。基于kringle结构域的表面和静电特征,讨论了它们之间的功能差异。