I solved a new crystal form of my protein today. In order to verify that the solution was right I generated a packing diagram, which is a sort of macro-view of the way that the molecules are arranged in the crystal lattice. If the molecules overlap - or clash - then the solution is wrong, since two objects can't occupy the same space. Equally, if the molecules aren't contacting one another at all then the solution is wrong because there would be nothing holding the crystal together. Well, my packing diagram showed that all was well with the solution - just enough touching and no overlaps - but there was an added bonus:
It looks like a snowflake! A Christmas miracle? Hardly. My crystals have six-fold symmetry, which happens to be the same as snow flakes (most of the time). Below is a side view of the packing diagram, which gives you a better idea of the 3D structure of the crystal:
You can see the snowflake shape runs right through the crystal. From this view it's not hard to imagine why my crystals grow as hexagonal rods - because their molecular structure is a series of hexagonal rods. And here is a slightly different view of the packing - a second snowflake!
Merry almost Christmas!
- Mr. Ed
No comments:
Post a Comment
Note: only a member of this blog may post a comment.