Blanco J, Jacotot E, Callebaut C, Krust B, Hovanessian A G
Unité de Virologie et Immunologie Cellulaire, UA CNRS 1157, Institut Pasteur, Paris, France.
Adv Exp Med Biol. 1997;421:193-9. doi: 10.1007/978-1-4757-9613-1_25.
By using a CD26 negative human lymphoblastoid cell line (C8166), here we describe the characterization of a cell-surface protein which manifests CD26-like dipeptidyl peptidase IV (DPP IV) activity. This protein, referred to as DPP IV-beta, shows a higher KM value for Gly-Pro-pNA than CD26 (0.31 mM compared to 0.11 mM, respectively). In addition, DPP IV-beta was found not to bind 125I-labeled adenosine deaminase (a property of human CD26). Gel filtration experiments using extracts from C8166 and MOLT4 (a CD26 positive human T cell line) cells, revealed that the apparent molecular mass of DPP IV-beta is 82 kDa, whereas that of CD26 is 110 kDa. In order to conveniently differentiate both activities, a new family of inhibitors, that selectively blocks peptidase activity associated to CD26, has been developed.
通过使用CD26阴性的人淋巴母细胞系（C8166），我们在此描述了一种表现出CD26样二肽基肽酶IV（DPP IV）活性的细胞表面蛋白的特性。这种蛋白被称为DPP IV-β，与CD26相比，它对甘氨酰-脯氨酰-对硝基苯胺（Gly-Pro-pNA）的米氏常数（KM）更高（分别为0.31 mM和0.11 mM）。此外，发现DPP IV-β不结合125I标记的腺苷脱氨酶（人CD26的一种特性）。使用C8166和MOLT4（一种CD26阳性的人T细胞系）细胞提取物进行的凝胶过滤实验表明，DPP IV-β的表观分子量为82 kDa，而CD26的表观分子量为110 kDa。为了方便区分这两种活性，已经开发了一类新的抑制剂，它们能选择性地阻断与CD26相关的肽酶活性。
