A high molecular weight form of met5-enkephalin-arg6-gly7-leu8 in rat brain and bovine adrenal chromaffin granules.

An antiserum against met5-enkephalin-arg6-gly7-leu8 (MAGL) has been used to identify various molecular weight forms of this immunoreactive material in brain and adrenal tissue. The predominant immunoreactive species in acid extracts of chromaffin granules eluted on Biogel P-30 as an approximately equal to 8,000 dalton peptide. Acid extracts prepared from rat brain medulla-pons also contained 8,000 dalton immunoreactive material which exhibited an identical retention time on HPLC to the corresponding immunoreactive material prepared from chromaffin granules.