Lynch D R, Strittmatter S M, Venable J C, Snyder S H
Endocrinology. 1987 Jul;121(1):116-26. doi: 10.1210/endo-121-1-116.
Enkephalin convertase (carboxypeptidase EH; EC 3.4.17.10), a carboxypeptidase B-like enzyme which processes hormone and neuropeptide precursors, has been characterized in the gastrointestinal tract, submandibular gland, and pancreas using a binding assay with [3H]guanidinoethylmercaptosuccinic acid. Binding to homogenates of the membrane and soluble fractions of stomach, small intestine, colon, and submandibular gland is saturable, with Kd values of about 2 nM. Partial purification of the membrane fractions reveals a Co+2-stimulated carboxypeptidase B activity which is not detectable in crude homogenates. In vitro autoradiography with [3H]guanidinoethylmercaptosuccinic acid localizes enkephalin convertase to the epithelial cells of the stomach, colon, and intestine, the islet cells of the pancreas, and the acinar cells of the submandibular gland. This localization contrasts to the distribution of enkephalins and other neuropeptides in the gastrointestinal tract and associated organs, suggesting that enkephalin convertase may serve functions other than neuropeptide and prohormone processing.
脑啡肽转换酶（羧肽酶EH；EC 3.4.17.10）是一种类似羧肽酶B的酶，可加工激素和神经肽前体。利用[3H]胍基乙硫基琥珀酸结合测定法，已在胃肠道、颌下腺和胰腺中对其进行了表征。与胃、小肠、结肠和颌下腺的膜匀浆及可溶性部分的结合是可饱和的，解离常数（Kd）值约为2 nM。膜部分的部分纯化显示出一种钴离子（Co+2）刺激的羧肽酶B活性，在粗匀浆中无法检测到。用[3H]胍基乙硫基琥珀酸进行的体外放射自显影将脑啡肽转换酶定位到胃、结肠和小肠的上皮细胞、胰腺的胰岛细胞以及颌下腺的腺泡细胞。这种定位与胃肠道及相关器官中脑啡肽和其他神经肽的分布不同，表明脑啡肽转换酶可能具有神经肽和激素原加工以外的功能。
