Interaction and biophysical properties of human lens Q155* betaB2-crystallin mutant.
Interaction and biophysical properties of human lens Q155* betaB2-crystallin mutant.
复制标题
DOI：
--
复制
发表时间：
2005-04
期刊：
影响因子：
2.2
通讯作者：
Bingfen Liu;Jack Liang
中科院分区：
文献类型：
--
作者：
Bingfen Liu;Jack Liang
目的在常染色体显性遗传性先天性白内障中发现晶体蛋白基因的错义突变。截短的HIBB 2基因（Q155*）与天蓝色白内障有关，但其对生物物理特性的影响尚未报道。我们试图确定这种突变所带来的构象和蛋白质-蛋白质相互作用的变化。方法通过定点突变获得Q155* betaB 2-crystallin突变体。通过哺乳动物双杂交系统测定筛选蛋白质-蛋白质相互作用。构象变化进行了研究，光谱（圆二色谱和荧光）和FPLC色谱。结果我们检测到Q155* betaB 2-晶状体蛋白突变体的蛋白质-蛋白质相互作用减少。Q155* 突变体显示有序结构和稳定性降低，但部分未折叠的蛋白质保留一些二聚体结构。结论：β B2-晶状体蛋白Q155* 突变导致生物物理特性的改变，可能有助于白内障的形成。
PURPOSE Missense mutations in crystallin genes have been identified in autosomal dominant congenital cataracts. A truncation in the CRYBB2 gene (Q155*) has been associated with cerulean cataract, however its effects on biophysical properties have not been reported. We sought to determine the changes in conformation and protein-protein interactions brought about by this mutation. METHODS Site specific mutations were performed to obtain the Q155* betaB2-crystallin mutant. Protein-protein interactions were screened by a mammalian two-hybrid system assay. Conformational changes were studied with spectroscopy (circular dichroism and fluorescence) and FPLC chromatography. RESULTS We detected a decrease in protein-protein interactions for the Q155* betaB2-crystallin mutant. The Q155* mutant shows decreased ordered structure and stability but the partially unfolded protein retains some dimer structure. CONCLUSIONS The Q155* mutation in betaB2-crystallin causes changes in biophysical properties that might contribute to cataract formation.