Gorman M A, De A, Freemont P S
Protein Structure Laboratory, Imperial Cancer Research Fund, London, England.
J Mol Biol. 1992 Dec 5;228(3):991-4. doi: 10.1016/0022-2836(92)90884-m.
Pancreatic spasmolytic polypeptide (PSP) isolated from porcine pancreas has been crystallized by the hanging drop vapour diffusion method. The crystals belong to the space group I222 or I2(1)2(1)2(1) with cell dimensions a = 181.9 A, b = 54.5 A, c = 72.9 A. The crystals diffract to at least 2.5 A resolution and the asymmetric unit contains two molecules (Vm = 3.9 A3/Da) with a solvent content of 68% as determined by density measurements of the crystals. The self-rotation function suggests that the two molecules within the asymmetric unit are related by a 2-fold axis at either 30 degrees or 60 degrees from a in a plane perpendicular to the b axis.
从猪胰腺中分离出的胰腺解痉多肽（PSP）已通过悬滴气相扩散法结晶。晶体属于空间群I222或I2(1)2(1)2(1)，晶胞参数a = 181.9 Å，b = 54.5 Å，c = 72.9 Å。晶体衍射至至少2.5 Å分辨率，非对称单元包含两个分子（Vm = 3.9 Å3/Da），通过晶体密度测量确定溶剂含量为68%。自旋转函数表明，非对称单元内的两个分子在垂直于b轴的平面内，通过与a轴成30度或60度的二次轴相关联。
