Hi Rafael, have you considered crystal dehydration? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3317743/ <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3317743/> It’s not easy to implement, but high solvent content could be a reason why your crystals don’t diffract beyond 4A. Did you manage to get some unit cell parameters from this 4A diffraction and estimate the solvent content? Good luck!
> On 17 Dec 2020, at 21:30, Rafael Marques <rafael_mmsi...@hotmail.com> wrote: > > Hello all, how are you doing? > > I have been working with two different proteins for 3 years. I was able to > purify them by IMAC and SEC, no problems at all, and I have got some crystals > of both. However, the best data I have got until now is around 4A. The > diffraction experiment was carried out several times at DLS. > > The crystals for each protein are different. One is really small whereas the > other one is a regular size (Images below). Some people have told me to try > microseeding and I did this, but with no success at all. > > So I am asking here if there is someone experienced in this kind of > witchcraft that could give me a hand and also answer me these two things: > > Have you ever had good size crystals that didn’t diffract beyond 4A and after > trying seeding you have got very good diffraction data (in these case with no > change concerning the crystal size)? > > What is the best protocol that you have tried to increase the size of your > crystals and make them diffract better? > > Many thanks in advance. > > Best > > <5A70957A7B3E4521AAC422B1E6B83034.png><F9E82659D7434ACEA3C00FF22CA3A3E6.png> > > > Rafael Marques da Silva > Mestrando em Física Biomolecular > Universidade de São Paulo > > Bacharel em Ciências Biológicas > Universidade Federal de São Carlos > > phone: +55 16 99766-0021 > > "A sorte acompanha uma mente bem treinada" > ________________________________________________ > > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > <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/
