Comments on: Practical Questions for Protein Crystallization

By: Sean

Sean — Sun, 26 Jul 2009 00:55:31 +0000

@DrSNo Did he already know the structure? I believe that I could solve a structure about that fast using FREE programs. I will have to play around and time myself one of these days

By: Raj Gosavi

Raj Gosavi — Wed, 22 Jul 2009 03:40:23 +0000

Here are some questions that can be added to the above list. In my experience these have been crucial too.

1. What temperature is optimum for crystallization?

2. Which tags and where (N-term or C-term or both) should be added and how to choose them?

3. How to design proper construct for proteins (N-term truncations or C-term truncations or both)?

4. Should I try to co-crystallize the protein with any substrate (peptide, ligand, nucleic acid, protein, etc..)?

By: Sean

Sean — Sat, 04 Jul 2009 16:37:41 +0000

@DrSNo: Thanks for the additional questions!

“you don’t have to know anything (much) about crystallography to solve a structure.”
I guess it depends on the structure, but there are some structures that are quite difficult that even those who study crystallography for years are unable to solve.

I would say that Wladek Minor is an expert in crystallography and has spent years studying the subject, the result: click, click, click – done. My fear is that there is a tendency to just simply click through the programs without considering the results of each step.

By: Sean

Sean — Fri, 03 Jul 2009 18:49:33 +0000

@Jinny: No secret, I didn’t think anyone really cared, so thanks for asking! I am currently living in Toledo, OH. Hmm, maybe I should put up a bio…

By: DrSNo

DrSNo — Fri, 03 Jul 2009 18:12:56 +0000

(1) Biggest Q, why do you need the structure, is it worth all the effort?
(2) you don’t have to know anything (much) about crystallography to solve a structure. Most structures are readily solved. Just click, click, click with your mouse and you might be done solving a structure in a day. Wladek Minor (UVA) solves a structure using HKL3000 in 30 min (seen him do it twice, and it was the same structure!). Clearly there can be numerous obstacles along the way. But before doing all the work, we imagine the easiest path possible.

By: DrSNo

DrSNo — Fri, 03 Jul 2009 18:02:40 +0000

3) How much will it cost to attain a protein crystal?
X-tal condition already known and just soaking in ligand? Cheap! Some say $5000. Include the time it takes to write paper and publish. Depends a lot on personnel costs. One structure I solved, took ~4 years from start of project to publication. 20+ constructs, 20+ purification with each purification requiring 7 different columns. Cost?? Too much (personnel costs being the highest). Impact factor, the highest. I think the structural genomic centers are down to $50000/structure. The biological value of most of those structures are very limited. How many structures of almost identical proteins from various bacteria do we need?

By: Jinny

Jinny — Fri, 03 Jul 2009 17:42:40 +0000

Where are you from? Is it a secret?

By: Sean

Sean — Wed, 01 Jul 2009 00:47:53 +0000

Thanks Bosco, but am unsure how this relates to this post. I am looking for questions about protein crystallization.

By: Bosco

Bosco — Wed, 01 Jul 2009 00:40:44 +0000

As a theorist, I found Lattman and Loll’s “Protein Crystallography: A Concise Guide” a really clear and concise explanation of the principles of crystallography.