[ccp4bb] Detergents to eliminate non specific aggregations
Hi, everyone, I can get my protein complex but there are some non-specific aggregation from the NMR spectra, and chaps can improve it. So, besides chaps, is there any other detergents to be used during crystal screening? All suggestions are welcome. ThanksRegards, Yuan
Re: [ccp4bb] reindexing monoclinic data
Gregory Bowman wrote: Yes, but I don't actually want to swap a and c (convention that a is shorter than c), but instead flip k and keep h and l the same. Incidentally, it is not immediately obvious to me why in matrix I cited below that the new l is h+l: -1 0 0 0 -1 0 1 0 1 Greg Because -a and c would give acute beta angle, by convention should be obtuse? attachment: example.gif
Re: [ccp4bb] reindexing monoclinic data
Sorry for adding confusion- of course in reciprocal space beta* should be acute. The figures should have been labeled a, c not h,L. Edward A. Berry wrote: Gregory Bowman wrote: Yes, but I don't actually want to swap a and c (convention that a is shorter than c), but instead flip k and keep h and l the same. Incidentally, it is not immediately obvious to me why in matrix I cited below that the new l is h+l: -1 0 0 0 -1 0 1 0 1 Greg Because -a and c would give acute beta angle, by convention should be obtuse?
Re: [ccp4bb] Detergents to eliminate non specific aggregations
Hampton makes a Detergent Screen that works the same way as the Additive Screen. http://hamptonresearch.com/product_detail.aspx?cid=1sid=39pid=31 It has 96 unique detergent reagents for crystal screening. It is a bit expensive, but if you don't want to purchase the whole kit you could just download the formulation table and then you will have a nice long list of possibilities. Mike - Original Message - From: 商元 shangyuan5...@gmail.com To: CCP4BB@JISCMAIL.AC.UK Sent: Saturday, August 27, 2011 4:55:27 AM GMT -08:00 US/Canada Pacific Subject: [ccp4bb] Detergents to eliminate non specific aggregations Hi, everyone, I can get my protein complex but there are some non-specific aggregation from the NMR spectra, and chaps can improve it. So, besides chaps, is there any other detergents to be used during crystal screening? All suggestions are welcome. ThanksRegards, Yuan -- Michael C. Thompson Graduate Student Biochemistry Molecular Biology Division Department of Chemistry Biochemistry University of California, Los Angeles mi...@chem.ucla.edu
Re: [ccp4bb] Methods for dehydrating crystals
Dear Andrea check out: Post-crystallization treatments for improving diffraction quality of protein crystals. Heras B, Martin JL. Acta Crystallogr D Biol Crystallogr. 2005 Sep;61(Pt 9):1173-80. All the best Savvas On 26 Aug 2011, at 22:53, Andrea L Edwards wrote: Hi all, What are the most successful methods you know of for dehydrating a crystal prior to freezing it? I am trying to push the resolution of my crystals. Thanks, Andrea
Re: [ccp4bb] Protein aggregation and crystallization
Hi, Anita If you could find a way to test the elute's activity/binding to its' substrat/cofactor, then you will learn much more about your target. If the function assay is elusive, you could try superose column (5KDa-5MKDa). Does your light scattering tell you about the estimated size and MW? Best, Joe On Sat, Aug 27, 2011 at 1:29 AM, anita p crystals...@gmail.com wrote: Hi Yury, I have done dynamic light scattering and it shows its polydispersed. Please let me know if it is still ok for setting trays. reg. anita On Fri, Aug 26, 2011 at 10:21 PM, Yuriy Patskovsky yuriy.patskov...@einstein.yu.edu wrote: Anita, an assembly may be quite large - I would check it somehow, maybe by light scattering or centrifugation Good luck Yury -- *From:* CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of anita p [crystals...@gmail.com] *Sent:* Friday, August 26, 2011 3:03 AM *To:* CCP4BB@JISCMAIL.AC.UK *Subject:* [ccp4bb] Protein aggregation and crystallization Hi All, I am working on a protein which has a membrane spanning region and as cytosolic domain.I have made various deletion constructs of the protein, so that I can have a crystallizable fragment. There is no homologues mentioned in the pdb for this protein. All of these constructs are purified successfully but when concentrated and loaded on a gel filtration column Superdex-200, they elute in the void volume. But the proteins donot precipitate out !! Is it worth while to go ahead for crystallization trials?? Any other suggestion is most welcome. Thanks Anita
