What's your monomeric molecular weight? Increased salt concentration can easily drive oligomerization.
What is your evidence that it interacts with the resin? Cheers, Chris -- Christopher L. Colbert, Ph.D. Associate Professor Department of Chemistry and Biochemistry North Dakota State University P.O. Box 6050 Dept. 2710 Fargo, ND 58108-6050 PH: (701) 231-7946 FAX: (701) 231-8324 From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK>> on behalf of Reza Khayat <rkha...@ccny.cuny.edu<mailto:rkha...@ccny.cuny.edu>> Reply-To: Reza Khayat <rkha...@ccny.cuny.edu<mailto:rkha...@ccny.cuny.edu>> Date: Wednesday, January 11, 2017 6:42 PM To: "CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK>" <CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK>> Subject: Re: [ccp4bb] Off-topic question about SEC All these make sense. Protein is very strange cause it goes from 60kDa (globular) to an apparent 360kDa. Process is reversible too. Reza Khayat, PhD Assistant Professor City College of New York Department of Chemistry New York, NY 10031 ________________________________ From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK>> on behalf of Keller, Jacob <kell...@janelia.hhmi.org<mailto:kell...@janelia.hhmi.org>> Sent: Wednesday, January 11, 2017 7:39 PM To: CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK> Subject: Re: [ccp4bb] Off-topic question about SEC Yes if it either A) oligomerizes B) significantly changes shape C) aggregates reversibly On option B: Lower NaCl could make the protein “appear” bigger by unfolding it a bit; hydrophobic interactions should be weaker in lower NaCl. JPK Artem www.harkerbio.com<http://www.harkerbio.com> "where wild SEC columns roam free" On Jan 11, 2017 7:22 PM, "Reza Khayat" <rkha...@ccny.cuny.edu<mailto:rkha...@ccny.cuny.edu>> wrote: Hi, Sorry for the off-topic question. Can a protein in lower [NaC] run faster on a SEC than at higher [NaCl] (i.e. elute at an earlier volume)? The protein elutes well within the resolution limits of the SEC with a symmetric gaussian A280 profile. I know that at lower [NaCl] the protein can elute later because it may interact with the matrix. Thanks. Best wishes, Reza Reza Khayat, PhD Assistant Professor City College of New York Department of Chemistry New York, NY 10031
