Hi, You may find helpful suggestions in Kiyoshi Nagai's papers (mid 80ies) who did this with haemoglobin (I could be wrong but I think he was the first to do this).
Cheers, Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel E-mail: bshaa...@bgu.ac.il Phone: 972-8-647-2220 Skype: boaz.shaanan Fax: 972-8-647-2992 or 972-8-646-1710 ________________________________________ From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Biswajit Pal [p...@ccmb.res.in] Sent: Monday, July 16, 2012 8:45 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Heme incorporation in expressed protein Dear all, Sorry for non-crystallography related question. We are trying to express an eukaryotic heme protein in E. coli. We are able to express it in soluble form. When we use 5-Aminolevulinic Acid, E. coli becomes brown. However, after cell lysis the soluble protein contains no heme and the pellet is brown. If we extract the pellet with detergent (Triton X-100 and Tween-20) the color comes in the supernatant, but there is no protein of our interest. These eventually indicate that the protein and heme are getting expressed/synthesized, but heme is not getting incorporated in the expressed protein. We would like to get this protein in heme-bound holo-form. Any suggestion to trouble-shoot this problem would be highly appreciated. Replies can be sent to me directly and I will post a summary on a later date. Thanks in advance, Sincerely yours, Biswajit Pal CCMB, Hyderabad, India