Abstract Adrenal proenkephalin contains the sequence AsnSerSer that is a typical site for the attachment of asparagine-linked carbohydrate. The 5300- and 18,200-Da bovine adrenal proteins derived from proenkephalin contain this recognition sequence and were therefore analyzed for the presence of both amino and neutral sugars. Less than 0.05 mol of amino sugar and less than 0.1 mol of neutral sugar were found per mole of each protein. No amino sugar was detected in other high-molecular-weight adrenal [Met]enicephalin-containing proteins. Together these findings indicate that bovine adrenal proenkephalin does not contain asparagine-linked carbohydrate.