People laughed when I said I wanted to crystallize membrane proteins – but now I have badgers
To put it simply: The process of photosynthesis involves lots of little protein components. If we find out the structure of these proteins we can start to understand how they work. We can find out the structure by crystallizing the protein and then firing X-rays at it (and doing some complicated maths).
Photosynthesis proteins are notoriously difficult/frustrating to crystallize (because they live in the cell membrane and don’t dissolve in water). I like a challenge, so 4 years ago I decided to myself that I really wanted to try to get some crystals. Working in a lab that deals with photosynthesis this year has enabled me to give it a go. Today I have these crystals – of a protein called LH2, which absorbs light in the first stage of photosynthesis in a bacteria called R. sphaeroides.
I’ve been developing purification and crystallization (or at least continuing the good work of my predecessors) for LH2 in order to get a better structure than the one we have already; the best for this species is a 6 angstrom EM projection map (Walz, et al., 1998 – J. Mol. Biol 282, 833-845).
The crystals I obtained were distinctly badger-shaped (or at least some other woodland creature, or beaver). Unfortunately these will be pretty useless for X-ray diffraction but they’re amusing nonetheless.
I also got some more likely-looking crystals, which should grow bigger in the next few days. At the moment it’s fantastic that I even got crystals, so if they diffract it will be an additional bonus. My future work will involve refining the purification/crystallization procedure to get better crystals.
On a side note, it’s a bit odd for me to get excited about a 6 angstrom resolution, considering the best structure I had last year (of a soluble protein) was to 1.7 angstroms.
In other news, I have secured a PhD position for next year. More on that story later.