摘要
空间群为Ｐ２１的Ａ１－（Ｌ－丙氨酸）胰岛素晶胞内，一个不对称单位含有一个六聚体，应用差值Ｆｏｕｒｉｅｒ技术，立体化学制最小二来技术和Ｘ—ＰＬＯＲ程序并辅以电子密度图的人工拟合，解析了分辨率ＡＩ—（Ｌ－丙氨酸）胰岛素（Ａｌ－Ｌ－ＡｌａⅠ）的晶体结构。最终Ｒ因子为２０．６％，与标准键长与键角的均方根偏差分别为和４．１９°，从电子密度图与模型的拟合来看，六聚体中每条Ａ链的Ａｌ位置替换的Ｌ—Ａｌａ清晰可见，每条Ｂ链Ｎ端Ｂ１—Ｂ８伏段都为α螺旋构象，形成了Ｂ１—Ｂ１９的连续α螺旋段。
The crystal structre of Al-(L-Ala) insulin (Al-L-Alal ) was determined at 2.5A resolution. It belongs to the monomic system with,space group p21. There is one hexamer molecule of Al- (L-Ala) insulin in an asymmetric unit. The molecular model was adjusted and refined by X-PLOR and stereochemically reshained least-squares programs, assisted by manual revision of the model based on difference Fourier maps. The final R-factor of Al L-Alal structure at 2.5A resolution is 0.206 with r.m.s. deviation of 0.022A from the ideal bond lengths and 4.19° from the ideal bond angles. The results show that the structural model of Al -L-Alal fitted well to the electron density maps. The electron density of six Al-L-Ala residues in the asymmetric unit is very clear. The formation of B1-B8 helix in each B-chain has made a continuous B1-B19 helix.
出处
《生物物理学报》
CAS
CSCD
北大核心
1994年第2期215-218,共4页
Acta Biophysica Sinica
基金
国家自然科学基金
学院重大项目基金
关键词
三维
晶体结构
胰岛素
丙氨酸
Monoclinic Al(L-Ala) insulin crystal Three-dimensional structure
