Electron microscopy of native and reconstituted alpha crystallin aggregates

The size and shape of native alpha crystallin aggregates extracted at either 4 degrees C (alpha c-crystallin) or 37 degrees C (alpha m-crystallin), were compared with each other, as well as with aggregates reconstituted from either pure alpha A or alpha B subunits using electron microscopy. The alpha B aggregates were the most uniform in size (about 9 nm in diameter) and the best stained. alpha A particles were about the same size as the alpha B, but the population distribution was broader and some indication of interparticle association was observed. alpha c particles exhibited a bimodal distribution, with one peak greater than the reconstituted particles and the other about the same size; alpha m was smaller than the reconstituted structures.