I observed 3-5 peaks for a baculovirus expressed protein once, and could only get good crystals if the peaks were crystallised separately, see: Virology 262, 333-343 (1999)
Virology 262, 333–343 (1999) Mark Quoting Ulli Hain: > Thanks for the suggestions/ideas. The protein is recombinantly > expressed in E.coli. It does in fact show a metal dependency. We mass > spec'd the peaks once looking for phosphorylation, which was not > detected, but we only got about 60-70% sequence coverage so it was > not very helpful. > > Quoting "Nadir T. Mrabet" <[email protected]>: > >> Given no info on the protein, it can be anything. >> Is it recombinant? Which host? etc. >> >> Oxydation (cys, met) is also a possibility >> By the way, deamination concerns asn and gln, not lys. >> >> Best, >> >> Nadir >> >> Pr. Nadir T. Mrabet >> Structural& Molecular Biochemistry >> Nutrigenex - INSERM U-954 >> Nancy University, School of Medicine >> 9, Avenue de la Foret de Haye, BP 184 >> 54505 Vandoeuvre-les-Nancy Cedex >> France >> Phone: +33 (0)3.83.68.32.73 >> Fax: +33 (0)3.83.68.32.79 >> E-mail: Nadir.Mrabet<at> medecine.uhp-nancy.fr >> >> >> >> On 18/02/2011 19:45, Soisson, Stephen M wrote: >>> Possibly deamidation of the protein, in particluar one or more >>> lysines. What does the Mass spec look like? >>> Cheers, >>> Steve >>> >>> ------------------------------------------------------------------------ >>> *From:* CCP4 bulletin board [mailto:[email protected]] *On >>> Behalf Of *Ulli Hain >>> *Sent:* Friday, February 18, 2011 12:14 PM >>> *To:* [email protected] >>> *Subject:* [ccp4bb] off-topic: 2 peaks on Cation >>> >>> Hi, I was wondering if anyone had possible explanations for a >>> recombinantly expressed soluble protein that runs as 2 equal, >>> slightly overlapping peaks on a cation exhanger but as one peak on a >>> size exclusion column and same electrophoretic mobility on SDS-PAGE. >>> -Ulli >>> >>> >>> Adelaide Ulricke Hain >>> PhD Candidate >>> Johns Hopkins Bloomberg School of Public Health >>> Department of Biochemistry and Molecular Biology >>> 615 North Wolfe Street >>> Baltimore, MD 21205 >>> Notice: This e-mail message, together with any attachments, contains >>> information of Merck& Co., Inc. (One Merck Drive, Whitehouse Station, >>> New Jersey, USA 08889), and/or its affiliates Direct contact information >>> for affiliates is available at >>> http://www.merck.com/contact/contacts.html) that may be confidential, >>> proprietary copyrighted and/or legally privileged. It is intended solely >>> for the use of the individual or entity named on this message. If you are >>> not the intended recipient, and have received this message in error, >>> please notify us immediately by reply e-mail and then delete it from >>> your system. >> Mark J van Raaij Laboratorio M-4 Dpto de Estructura de Macromoléculas Centro Nacional de Biotecnología - CSIC c/Darwin 3, Campus Cantoblanco 28049 Madrid tel. 91 585 4616 email: [email protected]
