White K C, Babbitt P C, Buechter D D, Kenyon G L
Department of Pediatrics, University of California, San Francisco.
J Protein Chem. 1992 Oct;11(5):489-94. doi: 10.1007/BF01025026.
The importance of creatine kinase (E.C. 2.7.3.2) in endocrine tissues has been generally overlooked. Using a specific radiometric assay, we have demonstrated the existence of CK in the Brockmann body (principal islet) of the Coho salmon. We have purified this protein from insular tissue and concurrently purified CK from brain and muscle of the salmon. Purification characteristics, immunological cross-reactivity, and N-terminal sequence analysis have demonstrated that the predominant cytosolic CK from the Brockmann body is indistinguishable from the BB (brain) isoenzyme. Immunocytochemical studies indicated that the enzyme resides in the endocrine parenchyma. Phosphocreatine may serve as a reservoir of energy in the islet and augment its capacity to secrete hormones. The induction of CK-BB in the islet by other hormones could influence the secretion of insular hormones. Interorgan flux of the substrate creatine may be an undescribed mechanism of physiological regulation.
肌酸激酶（E.C. 2.7.3.2）在内分泌组织中的重要性通常被忽视。通过一种特定的放射性测定法，我们已证明银大麻哈鱼的布罗克曼体（主要胰岛）中存在肌酸激酶。我们已从胰岛组织中纯化了这种蛋白质，同时也从大麻哈鱼的脑和肌肉中纯化了肌酸激酶。纯化特性、免疫交叉反应性以及N端序列分析表明，布罗克曼体中主要的胞质肌酸激酶与脑型（BB）同工酶无法区分。免疫细胞化学研究表明，该酶存在于内分泌实质中。磷酸肌酸可能作为胰岛中的能量储备，并增强其分泌激素的能力。其他激素对胰岛中脑型肌酸激酶（CK-BB）的诱导可能会影响胰岛激素的分泌。底物肌酸的器官间通量可能是一种未被描述的生理调节机制。
