1Agricultural Research Council, Institute of Animal Physiology, Babraham, Cambridge
2British Council Scholar. The Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw 22, Poland.
Tóm tắt
Abstract—The standardization of a radiochemical assay of choline acetyltransferase (acetyl‐CoA: choline‐O‐acetyltransferase EC 2.3.1.6. [ChAc]) is described. The method depends upon the use of [l‐C14]acetyl‐CoA as substrate and has been modified from the procedure originally published by MCCAMAN and HUNT (1965).The modified method gave results which were comparable with two methods depending on bioassay as the end step, which had previously given the highest recorded values for rabbit brain ChAc.Methods of extraction and activation of the enzyme were also investigated. The results showed that ether‐treated sucrose homogenates and cysteine‐saline extracts of acetone‐dried brain have comparable enzyme activities; both procedures give higher values than are obtained with untreated water homogenates, or sucrose homogenates treated with Nonex 501 or Triton X‐100.
