Inooka H, Kikuchi T, Endo S, Ishibashi Y, Wakimasu M, Mizuta E
Tsukuba Research Laboratories, Takeda Chemical Industries Ltd, Ibaraki, Japan.
Eur J Biochem. 1990 Oct 5;193(1):127-34. doi: 10.1111/j.1432-1033.1990.tb19313.x.
The conformation in solution of porcine brain natriuretic peptide was determined by combined use of NMR spectroscopy and distance geometry. A set of 157 inter-proton-distance constraints was derived from the two-dimensional NOE spectra, and further a set of three hydrogen bond constraints was obtained from analysis of the temperature dependence of labile protons. The five structures with minimal violations were selected after performing distance-geometry calculations starting from 40 random initial conformations. The distance-geometry structures were further refined by the use of restrained energy minimization and restrained molecular dynamics. This structure shows a compact conformation with the carboxy-terminal region, Asn21-Tyr26, folded back to the disulfide-linked loop region, Cys4-Cys20. The characteristics of the conformation determined are as follows: conformations of the three segments interposed by glycine residues, which are Arg7-Ile12, Ser14-Leu18 and Cys20-Arg25, were well defined and the segments Arg7-Ile12 and Cys20-Arg25 are rather close to each other and nearly parallel. The biological significance of these local conformations is discussed on the basis of comparisons with those of atrial natriuretic peptide reported by Kobayashi et al.
通过核磁共振光谱法和距离几何方法的联合使用，确定了猪脑钠肽在溶液中的构象。从二维NOE光谱中得出了一组157个质子间距离约束条件，并且通过对不稳定质子温度依赖性的分析进一步获得了一组三个氢键约束条件。从40个随机初始构象开始进行距离几何计算后，选择了五个违反情况最少的结构。通过使用受限能量最小化和受限分子动力学对距离几何结构进行了进一步优化。该结构呈现出紧凑的构象，其羧基末端区域（Asn21 - Tyr26）折叠回到二硫键连接的环区域（Cys4 - Cys20）。所确定构象的特征如下：由甘氨酸残基隔开的三个片段，即Arg7 - Ile12、Ser14 - Leu18和Cys20 - Arg25的构象明确，并且片段Arg7 - Ile12和Cys20 - Arg25彼此相当接近且几乎平行。基于与Kobayashi等人报道的心房钠尿肽的构象进行比较，讨论了这些局部构象的生物学意义。
