A unified method for purification of basic proteins

作者：Adhikari Sanjay^*; Manthena Praveen Varma; Sajwan Kamal; Kota Krishna Kiran; Roy Rabindra

来源：Analytical Biochemistry, 2010, 400(2): 203-206.

DOI：10.1016/j.ab.2010.01.011

• Protein purification
• Single step
• Ion-exchange chromatography
• Basic protein

Protein purification is still very empirical, and a unified method for purifying proteins without an affinity tag is not available yet. In the postgenomic era, functional genomics, however, strongly demands such a method. In this paper we have formulated a unique method that can be applied for purifying any recombinant basic protein from Escherichia coli. Here, we have found that if the pH of the buffer is merely one pH unit below the isoelectric point (pl) of the recombinant proteins, most of the latter bind to the column. This result supports the Henderson-Hasselbalch principle. Considering that E. coli proteins are mostly acidic, and based on the pl determined theoretically, apparently all recombinant basic proteins (at least pl-1 >= 6.94) may be purified from E. coli in a single step using a cation-exchanger resin. SP-Sepharose, and a selected buffer pH, depending on the pl of the recombinant protein. Approximately, two-fifths of human proteome, including many if not all nucleic acid-interacting proteins, have a pl of 7.94 or higher; virtually all these 12,000 proteins may be purified using this method in a single step.

• 出版日期2010-5-15