Purification and characterization of a novel cholesterol-lowering protein from the seeds of Senna obtusifolia  

作　　者：LI ChuHua1, LI Mei2, CHANG WenRui2 & GUO BaoJiang1 1 College of Life Sciences, South China Normal University, Guangdong Provincial Key Lab of Biotechnology of Plant Development, Guang-zhou 510631, China 2 Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China 

出　　处：《Science China(Life Sciences)》2008年第11期1020-1024,共5页中国科学（生命科学英文版）

基　　金：Guangdong Provincial Department of Science and Technology (Grant No. 2003C34409);Guangzhou Civil Department of Science and Technology (Grant No. 2002Z3-85041)

摘　　要："Juemingzi", a source of traditional Chinese herbal medicine, has been demonstrated to play a role in decreasing serum cholesterol concentration. In this study, a novel protein, which has shown an in-hibitory effect on cholesterol biosynthesis, was isolated from Senna obtusifolia L. seed by gel filtration and ion exchange chromatography. The novel protein’s molecular mass was 19.7 kD and its pI was 4.80. Both SDS-PAGE and isoelectric-focusing (IEF) revealed a single Coomassie brilliant blue stained band, indicating that the novel protein was a single peptide. The N-terminal amino acid sequence of the pro-tein was IPYISASFPLNIEFLPSE, which had no similarity with any other protein sequences in the NCBI protein database. Circular dichroism (CD) signals indicated that S. obtusifolia seed protein contained 12.5% α-helix, 55.6% β-sheet, and 31.9% random coil.'Juemingzi', a source of traditional Chinese herbal medicine, has been demonstrated to play a role in decreasing serum cholesterol concentration. In this study, a novel protein, which has shown an in-hibitory effect on cholesterol biosynthesis, was isolated from Senna obtusifolia L. seed by gel filtration and ion exchange chromatography. The novel protein’s molecular mass was 19.7 kD and its pI was 4.80. Both SDS-PAGE and isoelectric-focusing (IEF) revealed a single Coomassie brilliant blue stained band, indicating that the novel protein was a single peptide. The N-terminal amino acid sequence of the pro-tein was IPYISASFPLNIEFLPSE, which had no similarity with any other protein sequences in the NCBI protein database. Circular dichroism (CD) signals indicated that S. obtusifolia seed protein contained 12.5% α-helix, 55.6% β-sheet, and 31.9% random coil.

关 键 词：SENNA obtusifolia L. seed NOVEL PROTEIN purification biochemical properties CHOLESTEROL BIOSYNTHESIS 

分 类 号：Q51[生物学—生物化学]