抗菌多肽LC1的圆二色性和二级结构预测以及初步晶体学研究

CIRCULAR DICHROISM SECONDARY STRUCTURE PREDICTION AND PRELIMINARY CRYSTALLOGRAPHIC STUDIES OF A NEW ANTIBACTERIAL POLYPEPTIDE LC1

由远紫外圆二色谱算得枯草杆菌Ａ０１４（Ｂａｃｉｌｌｕｓｓｐｐ．）所分泌的新型抗菌多肽ＬＣＩ在水溶液中的各种构象含量为：α螺旋４．７—６．０％，β折叠６７．２－７２．８％，无规卷曲和转角２１．１－２８．１％。对多种方法的二级结构预测结果进行综合分析表明，ＬＣＩ可能含有３个β转角，４个β折叠片段，仅含少量或不合α螺旋．晶体最大线度可达０．２×０．２×０．４ｍｍ，属于三方晶系。其六方Ｈ晶胞为ａ＝ｂ＝５１．２１空间群为Ｒ３２。

LC1 is a new antibacterial polypeptide containing 47 usidues. Different conformation contents calculated from CD are: α-helix 4.7-6.0%, β-sheet 67.2-72.8%, coil and β-turn 21.2-28.1%. The predicted secondary structures include 3 β-turns, 4 shands of β-sheets and only a little or no α-helix. The result is consistent with that obtained from CD.Preliminary crystallographic studies show that Lc1 crystal belongs to trigonal crystal system and group R32 wb hexagonal H lattice a=b= There is one LCl molecule per asymmetric unit.