From nicolas.bazeille from curie.u-psud.fr Mon Feb 2 11:43:50 2009 From: nicolas.bazeille from curie.u-psud.fr (Nicolas BAZEILLE) Date: Mon Feb 2 12:27:24 2009 Subject: [Protein-analysis] hydroxyapatite columns problems Message-ID: <6.1.1.1.2.20090202172234.0b965330@pop.curie.u-psud.fr> Hi, I'm trying to purify protein using hydroxypapatite system from bio-rad. The purification step work well, but the powder is very hard to regenerated. I don't use any forbidden components in my buffer such EDTA or Tris. I use different kinds of regeneration pathways (500 mM phosphate, 1M NaOH, 6M guanidium chloride for short time) according to the supplier informations. However, after regeneration, the flow rate greatly decrease, and the powder seems to be damaged (it seems to be solubilize while solution containing phosphate). I don't want to use new product for each purification Is there a way to preserve the stability of the material ? Is somebody find the same problem? thanks in advance. M. BAZEILLE Nicolas Equipe XI G?notoxicologie et cycle cellulaire - UMR 2027 CNRS/Institut Curie Centre Universitaire B?timents 110 91405 ORSAY Cedex 01-69-86-71-27 From ql5 from ualberta.ca Wed Feb 4 00:57:57 2009 From: ql5 from ualberta.ca (Qin Liu) Date: Wed Feb 4 10:06:07 2009 Subject: [Protein-analysis] Reagents which are membrane permeant Message-ID: <3582E7A05A5E434597BB715A4913CDEF@qin> Hi, I'm wondering if DTT is ER membrane permeant. Also, if anyone can = recommend some ref which I can find more information about reagents = which are membrane permeant. Thanks in advance, QinFrom ql5 from ualberta.ca Wed Feb 4 02:01:25 2009 From: ql5 from ualberta.ca (Qin Liu) Date: Wed Feb 4 10:06:13 2009 Subject: [Protein-analysis] reagent which are membrane permeant References: <200901301704.n0UH49806820@net.bio.net> Message-ID: <45611CFB7571492F91565A676D49B0EA@qin> Hi, I found that it seems the hydrophobicity of reagent is not related to the membrane permeanbility. I'm wondering how to judge if a reagent is membrane-permeant or not. I appreciate any comments. Thanks, Qin From engelbert_buxbaum from hotmail.com Sun Feb 8 15:21:36 2009 From: engelbert_buxbaum from hotmail.com (Dr Engelbert Buxbaum) Date: Sun Feb 8 17:22:29 2009 Subject: [Protein-analysis] Re: hydroxyapatite columns problems References: Message-ID: Am 02.02.2009, 12:43 Uhr, schrieb Nicolas BAZEILLE : > Hi, > > I'm trying to purify protein using hydroxypapatite system from bio-rad. > The purification step work well, but the powder is very hard to > regenerated. > I don't use any forbidden components in my buffer such EDTA or Tris. > I use different kinds of regeneration pathways (500 mM phosphate, 1M > NaOH, 6M guanidium chloride for short time) Hydroxyapatite is a crystalline form of calcium phosphate. It is easier to use with a ceramic backbone (BioGel HTP). I am not sure why you use conditions like NaOH or guanidinium chloride, with a properly prepared sample that should not be necessary. From sticher from bioc.uzh.ch Wed Feb 11 11:15:24 2009 From: sticher from bioc.uzh.ch (Patrick Sticher) Date: Wed Feb 11 12:41:08 2009 Subject: [Protein-analysis] First Announcement: 7th International NCCR Symposium on New Trends in Structural Biology Message-ID: <4992F99C.70901@bioc.uzh.ch> Dear colleagues, it is our pleasure to announce the 7th International NCCR Symposium taking place this September. First Announcement: 7th INTERNATIONAL NCCR SYMPOSIUM ON NEW TRENDS IN STRUCTURAL BIOLOGY September 7 + 8, 2009 Lecture Hall HG F7, Swiss Federal Institute of Technology (ETH) Zurich, Switzerland This symposium brings together renowned scientists in structural biology from all over the world to exchange their knowledge and current research ideas in an interactive way. The symposium addresses latest developments and perspectives in the areas of membrane proteins, supramolecular assemblies & interactions, as well as in the fields of related technologies. www.structuralbiology.uzh.ch/symposium2009 The registration slot opens end of March. Online registration will be possible directly from the above mentioned web site. We do hope that this conference is of interest to you and would be pleased to welcome you in Zurich this fall. With best regards, Patrick Sticher _________________________________ Visit the NCCR on the Internet www.structuralbiology.uzh.ch Dr. Patrick Sticher Moser NCCR Scientific Officer Institute of Biochemistry University of Z?rich Winterthurerstrasse 190 CH - 8057 Z?rich From sumida from bbri.org Fri Feb 20 12:46:17 2009 From: sumida from bbri.org (jps) Date: Fri Feb 20 13:49:04 2009 Subject: [Protein-analysis] proteins that don't ionize Message-ID: <864ce66f-5dcc-4240-b110-31976e57bb31@q25g2000vbn.googlegroups.com> Recently purified an unknown protein with a partial N-terminal sequence match to a bacterial outermembrane protein. Oddly this protein does not react with DTNB, does not seem to ionize when mixed with sinnapinic acid and placed in a MALDI-ToF, and has a molecular weight of 33kDa as judged by SDS PAGE analysis. Curious to know if anybody thinks that membrane proteins would have more difficulty interacting with MALDI matrices than other proteins?