蓝隐藻PC645两种β亚基的分离及空间结构差异性
Isolation and Spatial Structure Diversity of Two β Subunits of PC645 from Chroomonas placoidea
张昆 1王静 1王宇涵 1李琴 1陈敏1
作者信息
- 1. 烟台大学生命科学学院,山东 烟台 264005
- 折叠
摘要
为了确认蓝隐藻(Chroomonas placoidea T13)藻蓝蛋白PC645 中新发现的β亚基的空间结构差异性,以纯化的C.placoidea PC645 为材料,经6 mol/L尿素变性后,摸索了两次DEAE Sepharose Fast Flow阴离子交换层析法,大规模分离得到了β1 亚基和两种β2 亚基洗脱样品.吸收光谱表明所得的这三种β亚基洗脱组分均保持着活性状态.圆二色谱(CD)显示,β1 亚基与两种β2 亚基的可见光区CD谱相近,但远紫外区和近紫外区光谱存在不同,这说明两种β亚基具有相同的色基组成,但其蛋白质的二、三级空间结构存在差异,其中β1 亚基中α-螺旋的比例高于β2.上述结果不仅进一步确定了新的β亚基的存在,也为重新认识特异的隐藻藻胆蛋白的亚基组成和组装方式提供了实验依据.
Abstract
In order to identify the spatial structure diversity of a new β subunit found in phycocyanin PC645 of Chroomonas placoidea T13,a large-scale of separation procedure of two steps of DEAE sepharose fast flow anion ex-change chromatography is established and by which a β1 subunit and two β2 subunits components are eluted after 6 mol/L urea denaturation of purified PC645 from self-cultured C.placoidea.The absorption spectra results confirm that the three β subunits elutes are all remained in active state.The circular dichroism(CD)shows that the β1 subunit exhibits similar CD features in visible region to the two β2 subunits,but varies both in the far and near ul-traviolet region.This result indicates that the two types of β subunits have the same bilin composition,but the sec-ondary and tertiary spatial structure of proteins are different.The β1 subunit possesses higher proportion of α helix than that of β2.The results above not only furtherly confirm the existence of new β subunit,but also provide a di-rect experimental basis for re-understanding of the subunit composition and assembly of the specific cryptophytic bil-iproteins.
关键词
蓝隐藻/PC645/β亚基/圆二色谱/空间结构差异Key words
Chroomonas placoidea/PC645/β subunit/circular dichroism/spatial structure diversity引用本文复制引用
基金项目
山东省自然科学基金(ZR2018LD009)
出版年
2024
国家科技期刊平台
NSTL
万方数据