Fate of collagen-tailed acetylcholinesterase upon extraction of chick retina with salt-detergent solutions in the absence of EDTA.

In chick retina, the tailed 20S molecular form of acetylcholinesterase (A12) is slowly degraded to globular forms after homogenization of the tissue in a buffer-salt-detergent solution, in the absence of EDTA. This process can be stopped by the addition of EDTA to the homogenate, prior to high speed centrifugation; however, longer delays in adding EDTA lead to lower recoveries of tailed enzyme. The rate of degradation of A12 is considerably enhanced by high speed centrifugation of this EDTA-less homogenate prior to addition of EDTA.