Hi Deepak, If this is a metalloprotein, include higher concentration of the metal in the crystallization drop. It may act as a glue in the interfaces and give you a good crystal.
Jackie Vitali Cleveland State University On Tue, May 18, 2021 at 6:20 AM Deepak Deepak <deepmalik...@gmail.com> wrote: > Dear all, > > I have got multiple crystals (see picture 1) of a protein (8kDa) with a > helical aromatic oligoamide foldamer (5kDa) but these crystals *diffract > very poorly *(see the diffraction pattern in picture 2). > > I prepare a 1.3mM:1.3mM complex of protein: foldamer in 20mM Tris, pH 7.5 > buffer. Crystals grew in 3-5 days in sitting and hanging drop at 20 Deg C > and 25 Deg C in the following conditions: > > *- 20% PEG 400, 0.1M MES pH 6.0* > *-20% PEG 400, 0.1M Sodium Cacodylate pH 6.0* > > *Multiple cryo used were:* > *-25%Glycerol in mother solution* > -30% glycerol in water > *-30%PEG 400,* > *-35% PEG 400* > *-20% PEG 8000 + 40% PEG 400 mix* > > Kindly suggest some methods/modifications on how can I improve the > resolution and get better-diffracting crystals. Please let me know if you > need more information. > > Kind regards, > Deepak > Ph.D. Student > > PS: The protein is a DNA binding protein and I have crystallized and > solved the structure of this protein with its DNA partner and now I > crystallized it with our foldamers but diffraction is not good. There are > multiple structures of the Protein+DNA complex in literature but *no > apo-protein structure *as the protein needs a binding partner to > crystallize. *We already have solution studies showing a good binding.* > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
