[Protein-analysis] Re: NMR vs X-ray : protein structure

[Dr Engelbert Buxbaum]

DK wrote:

> >info. In addition because of high-throughput screening techniques
> >protein crystallisation is no longer the black magick it used to be.
> 
> It still is. HTS only picks low hanging fruit and even then many crystal 
> don't diffract and require lots of effort and luck to rescue them. Anything
> that does not like to crystallize, and HTS won't help you any because the 
> bottleneck is in knowing what to express, where and how. 

I have never done it myself, but from the literature (Kimber et al.
2003) it would appear that in a HTS screen you nowadays get about 2/3 of
the proteins to crystallise with only a small number (6) of tested
conditions, moderate increase to 24 conditions brought crystalls for 91%
of the proteins. That is not too bad. 

Of course these numbers are for soluble proteins, membrane proteins are
a different kettle of fish, altogether.