[每日一文]酿酒酵母表达的rHBcAg颗粒的纯化和鉴定及其透射电镜观察
酿酒酵母表达的rHBcAg 颗粒的纯化和鉴定及其透射电镜观察
陈 恒1, 2, 3,梁婉琪3,张大兵3**
(1. 上海交通大学生命科学技术学院,上海 200030; 2. 上海大学生命科学学院,上海 200436;
3. 上海市农业科学研究院生物技术中心,上海 201106)
Purification and Observation of the Recombinant Hepatitis B Virus Core
Antigen (rHBcAg) Particles Produced in the Yeast
CHEN-Heng1, 2, 3, LIANG Wan-qi3, ZHANG Da-Bing3**
(1.School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200030,China; 2. School of Life
Science, Shanghai University, Shanghai 200436,China; 3. Biological Technology Center of Shanghai Agriculture Science
Institute, Shanghai 201106,China)
Abstract: Hepatitis B virus core antigen protein gene (C gene) was expressed in Saccharomyces
cerevisiae and the products (rHBcAg particles) were purified from crude lysate of the yeast by three
steps: Sephrose CL-4B chromatography, sucrose step-gradient ultracentrifugation, and CsCl-isopycnic
ultracentrifugation. rHBcAg was synthesized in yeast cells as a particle consisting of polypeptides
which have a molecular weight of 21.5 kDa (p21.5). ELISA and CsCl- isopycnic ultracentrifugation
purification products (rHBcAg particles) in each fraction indicated that the particle densities of the
fraction with higher rHBcAg antigenicity mainly distributed at the densities of 1.27g·mL-1 and 1.40
g·mL-1, respectively. Observation of the purified products (rHBcAg particles) by TEM indicated that
rHBcAg peptides could self-assemble into two kinds of different sizes of rHBcAg particles (core
particles); the large particle was about 30.1±2.4 nm in diameter and the small particle about 21.5±3.3
nm. This indicated that the rHBcAg particles displayed dimorphism, but the biological significance of
this dimorphism is not clear and needs to be studied further.
Key words: rHBcAg; Saccharomyces cerevisiae; rHBcAg particles; Ultracentrifugation; Transmission
electron microscopy
摘要:乙肝核心抗原(HBcAg)蛋白基因(C 基因)在酿酒酵母中表达,表达产物经过分离和Sepharose CL-4B 柱子
的初步纯化。产物经SDS-PAGE 和Western blotting 鉴定为一分子量约21.5kDa 的多肽。再经蔗糖密度梯度超离心
和CsCl 等密度梯度超离心等过程而被纯化。分管收集的超离心纯化产物经ELISA 抗原活性检测和密度分析,可
知ELISA 反应强度较高的收集管中的颗粒密度主要分布在1.27g/mL 和1.40 g/mL 两个峰值处。将rHBcAg 抗原活
性最高的收集管合并,再经TEM 观察,发现酵母表达的rHBcAg 蛋白(核心蛋白)能自主装配成大小不同的两
种核心颗粒,大颗粒直径约为30.1±2.4 nm,小颗粒直径约为21.5±3.3 nm。这表明,酿酒酵母表达的rHBcAg
颗粒具有大小不同的二态性,其生物学意义还未明了,需进一步研究和探讨。
关键词:重组乙肝核心抗原蛋白(rHBcAg protein); 酿酒酵母(Saccharomyces Cerevisiae);核心抗原颗粒(rHBcAg
particles); 超离心; 透射电子显微镜
中图分类号:Q5 文献标识码:A 文章编号:1003-5152(2004)02-0101-04
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