[ccp4bb] precipitation of the protein in crystallisation solution

2009-06-02 Thread peter hudson
Hello all I am working on small protein-protein complex of 10 kDa each component.Among these complex one of the partner known to be highly flexible but in complex they are suppose to be well structured and from a tight complex . I am trying to crystallise this complex. When i add the protein in

Re: [ccp4bb] precipitation of the protein in crystallisation solution

2009-06-02 Thread Matthew Alan Bratkowski
Hi Peter, You first want to reduce the protein concentration to avoid rapid precipitation upon adding crystallization solutions. Try concentrations of 5 - 10 mg/mL instead of 15 mg/mL. Next, consider changing the NaCl concentration. Salt can act as a co-precipitant, and lowering its concentrati

Re: [ccp4bb] precipitation of the protein in crystallisation solution

2009-06-03 Thread Enrico Stura
Given that you are able to achieve a protein concentration of 15 mg per ml in Tris-HCl, pH 8.0, 100mM NaCl and 1% Glycerol suggests that you have no drastic solubility problem. Unless you have a chromatophore as an intrinsic co-factor of one of your component proteins, the yellow slime may be due