Dear All, I have a trimeric molecule (~39 kDa, pI=9.1) carrying 15 lysines in each monomer. I have tried several crystallization screens, however, I mostly get clear drops. The only conditions that I tend to get precipitates in, are the ones carrying citrate. I am beginning to methylate the lysines or remove a few of those by mutagenesis.
I would be grateful if somebody could share their experience in crystallization of proteins with a high number of lysines. Also, any inputs on strategies to crystallize such molecules would be greatly appreciated. Many thanks in advance. -- Amit Sharma
