Protein Extraction Methods for Two-Dimensional Electrophoresis from Baphicacanthus cusia （Nees）Bremek Leaves-A Medicinal Plant with High Contents of Interfering Compounds

• Published in: Agricultural sciences in China no. 10; pp. 1530 - 1537
• Main Author: XIANG Xiao-liang NING Shu-ju JIANG Xia GONG Xiao-gui ZHU Ren-lei WEI Dao-zhi
• Format: Journal Article
• Language: English
• Published: 2010
• Subjects: 二维电泳; 化合物; 提取方法; 次生代谢产物; 自主知识产权; 药用植物; 蛋白质提取
• ISSN: 1671-2927

Protein extraction is a critical step for two-dimensional electrophoresis （2-DE）. Different plant samples require different and adaptive protein extraction protocols. The leaves of medicinal plant, Baphicacanthus cusia （Nees） Bremek are notoriously recalcitrant to common protein extraction methods due to high levels of interfering compounds （especially the secondary metabolites and pigments）. This study was aimed to establish a routine procedure for the proteomic analysis ofB. cusia leaves, and a new protocol for the protein extraction was developed by optimizing trichloroacetic acid （TCA）/ acetone extraction method. The efficiency of this protocol was demonstrated by comparison with 3 published protein extraction methods （chloroform/acetone, Mg/NP-40, Tris-base/acetone）. The results showed that the optimized TCA/ acetone precipitation extraction method gave a relatively high protein yield （9.263 mg g^-1 fresh weight）, high-resolution separation, clear protein profiles, the highest proteins spots （1 31 t protein spots）, and displayed less contamination in 2- DE gels. Therefore, the results suggested that the optimized TCA/acetone method was the most effective among the 4 methods for B. cusia leaves.