摘要
以人白介素2晶体结构为模板同源模建人白介素15及其两株突变体 (N端缺失4个氨基酸、C端缺失3个氨基酸 )的空间构象。在CVFF力场下 ,经过分子力学优化、常温分子动力学模拟获得稳定立体结构模型。借助空间构象残基的亲疏水性分析 ,利用Delphi程序定性分析蛋白表面静电分布 ,进而从理论上预测人白介素15及两株突变体生物学功能的相似性、差异性。结合分子生物学实验 ,在 pBV220载体中克隆表达获得人白介素15及两株突变体 ,通过刺激CTLL -2细胞增殖、诱导外周血白细胞LAK活性实验探讨三株蛋白的生物学功能 ,与理论预测结果一致。
The three dimensional (3-D) structure of IL-15 and its two mutants (4 amino acids-deleted at N-terminal or 3 amino acids -deleted at C-terminal) are constructed by means of computer-guided homology modeling techniques with the crystal structure of IL-2 as a template. The structures are optimized with molecular mechanism and molecular dynamics under CVFF-force field. Furthermore, the similarity and difference of the three proteins in biological activities are predicted based on the analysis of residues hydrophilic and hydrophobic characteristics and surface electrostatic potential distribution of these proteins. IL-15 and its two mutants are expressed in E.coli and their bioactivities are tested with CTLL-2 proliferation assay and LAK-induction assay. The results show that N-terminal mutant loses CTLL-2 proliferation stimulation activity but keeps the LAK-induction activity from PBMC,while C-terminal mutant increases both of the two bioactivities. These results correspond to the predictions.
出处
《生物物理学报》
CAS
CSCD
北大核心
2000年第2期310-314,共5页
Acta Biophysica Sinica
