Easier Way to Convert Proteins into Crystals

Roland Piquepaille writes "As you might know, proteins need to be transformed into 3-D crystals before their atomic structures and their properties can be analyzed. And production of high quality crystals from proteins has been a difficult task until now. But scientists in the U.K. have successfully used a porous medium, or 'nucleant,' a material that encourages protein molecules to crystallize. Their first step towards 'holy grail' of crystallography could help speed up the development of new medicines and treatments."

Comments

This is Big

[eldavojohn]

Ok, so I don't know a ton about nuclear medicine, I know just enough to be dangerous. Protein crystallization allows us to see it's structure whereby we better understand its function.

The reason this bit of news is so big is that it will (hopefully) allow researchers a way to quickly look at the structures of proteins in such as (in the second link) infectious diseases transmitted by prions, or protein particles. Prions seem to be pure protein; they contain neither DNA nor RNA.

If we can understand the shape and formation of proteins, we can understand how viruses and cells work because proteins are the building blocks. Viruses are obviously first on the chopping block as they are the smallest and infect millions of people world wide (AIDS, influenza, the common cold, etc.).

Re:This is Big

[ruckerz2k]

Though the parent is correct, this technology greatly reduces the time and effort involved in 'crystallizing' proteins. Most common approach is to use the hanging drop method, where a drop of the sample is suspended over a highly concentrated solution. The sample concentrates due to the negative osmotic pressure and the protein 'crystallizes'. The crystallization process can be hastened by using a 'nucleant', usually a small crystal of the sample that you have previously crystallized. Also, the exact identity and composition of the concentrated solution is varied in order to find the right crystallization conditions. This is a very tedious process (imagine setting up 96 different concentrated solutions, each differing in about 1% concentration of the solutes) and time intensive.

The discovery of a 'universal' nucleant (close to the one suggested by the authors of this study) and the development of a matrix to encourage crystallization would greatly speed the screening process, and ultimately, crystallization of proteins.

Nobel Prize material

[smellsofbikes]

To find the three-d structure by x-ray crystallography, you have to crystallize the protein. Actually doing so, with different proteins, is an astoundingly difficult task, so much so that something like five Nobel prizes have been given for research into crystallization and x-ray crystallography development, and another ten or so Nobels given for determination of three-d structure of various proteins were, in essence, awarded for getting the protein to crystallize.

Side story: there was a famous German chemist named Emil Fischer, who originally determined the structures of a bunch of sugars. That was, again, largely a crystallization problem. He had, as Germans did in the 1890's, an enormous beard, and was playing with chemicals all day long, which tended to condense in his beard. It was said that if you could not get something to crystallize out of solution, no matter what you did, you asked Fischer to come to your lab and fluff his beard over your beaker, and the seed crystals falling from it were of such variety that one was almost guaranteed to be correct for your particular situation and get it to crystallize. So this isn't exactly NEW technology.

This should impact future graduate students

[radiashun]

Hopefully this will encourage more individuals to pursue advanced degrees in protein crystallography. I was recently at a talk where a soon-to-be PhD was discussing her crystallography work. She said that many people choose to pursue other areas in biochemistry/structural biology because protein crystallography is very unpredictable. Some proteins will crystallize in months while others can take YEARS! Waiting years before you can really dive into your PhD research is very discouraging.

Re:This is Not so Big

[sam_handelman]

This is an improvement on a known technique. The abstract is as over-reaching as the press release (the linked article).

  I'm not a crystallographer, but I work in a lab group that has many crystalographers in it.

  It's been known for some time that you can use a variety of materials - including things with porous surfaces, which is what is used here - to assist the process of crystallization. Crystalization is difficult and, frankly, rather unscientific - you take the protein you want to crystallize, and you try different techniques and tricks (of which porous nucleants are an example) until you can get it to work.

  So, okay, it would be a "holy grail" if you could find one technique that would let you crystallize most things without going through all that trouble.

  However, based on only seven examples (Subscribers only, I'm afraid.), you absolutely cannot conclude that this is a universal nucleant - based on the similarity among the seven examples, I'd be very surprised if it were; even if it were a universal nucleant, nucleation does not always guarantee usable crystals.

  Those caveats aside, it does look like a useful advance.