Re: [ccp4bb] Insoluble ligand?

[Roger Rowlett]

Keep in mind it may also be possible to soak in ligand from the solid if the binding constant is tight enough. Le Chatelier's principle will drag it from the undissolved solid into the complex. This process will be improved if you can increase solubility in solution, e.g. by incuding 20% DMSO or some other cosolvent in your drop. If you crystals will tolerate some cosolvent without cracking or dissolving, the equilibrium concentration of ligand in solution may still be high enough to populate your protein. This won't work for a loose-binding ligand. Cheers, _______________________________________ Roger S. Rowlett Gordon & Dorothy Kline Professor Department of Chemistry Colgate University 13 Oak Drive Hamilton, NY 13346 tel: (315)-228-7245 ofc: (315)-228-7395 fax: (315)-228-7935 email: rrowl...@colgate.edu On 9/16/2011 12:04 PM, Chaudhary, Ritcha wrote: Hi All I have a ligand that is dissolved in 100% DMSO. The ligand crashes out even when diluted to 20% final DMSO concentration in the protein buffer. I have heard of people using detergents such as n octyl Beta D glucoside to keep the ligand solubilized at lower DMSO concentrations. Can someone give me pointers in this direction? Any suggestions, references etc..... Thanks much Ritcha