Liu J Y, Zhang J P, Wan Z L, Liang D C, Zhang J P, Wu H J
State Key Laboratory, of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
Acta Crystallogr D Biol Crystallogr. 1998 Jul 1;54(Pt 4):662-4. doi: 10.1107/s0907444997017824.
Allophycocyanin from red alga Porphyra yezoensis has been crystallized in three crystal forms. Form 1 crystals with space group P4132 or P4332 and cell parameters a = 286 A, alpha = 90 degrees were obtained by using isopropanol as precipitant. These crystals did not diffract beyond 5.8 A and could not be used in structure analysis. Form 2 crystals were obtained when crystallization conditions were slightly changed by adding 0.2 M magnesium chloride. The space group of form 2 was not determined because it was difficult to get large single crystals. Form 3 crystals were obtained by using ammonium sulfate as precipitant. The space group of form 3 is R32 with cell dimensions a = b = 105.3, c = 189.4 A and one alpha beta unit in the asymmetric unit. These crystals diffract up to 2.06 A resolution and are suitable for structure determination by molecular-replacement methods.
来自红藻条斑紫菜的别藻蓝蛋白已结晶为三种晶体形式。通过使用异丙醇作为沉淀剂，获得了空间群为P4132或P4332且晶胞参数a = 286 Å、α = 90°的1型晶体。这些晶体在5.8 Å以上不发生衍射，不能用于结构分析。当通过添加0.2 M氯化镁稍微改变结晶条件时，获得了2型晶体。由于难以获得大的单晶，2型晶体的空间群未确定。通过使用硫酸铵作为沉淀剂，获得了3型晶体。3型晶体的空间群为R32，晶胞尺寸a = b = 105.3、c = 189.4 Å，不对称单元中有一个αβ单元。这些晶体的衍射分辨率高达2.06 Å，适用于通过分子置换法进行结构测定。
