Barsun Marina, Jajcanin Nina, Vukelić Bojana, Spoljarić Jasminka, Abramić Marija
PLIVA Research and Development Ltd., Prilaz baruna Filipovića 25, 10000 Zagreb, Croatia.
Biol Chem. 2007 Mar;388(3):343-8. doi: 10.1515/BC.2007.039.
Dipeptidyl peptidase III (DPP III) is a zinc exopeptidase with an implied role in the mammalian pain-modulatory system owing to its high affinity for enkephalins and localisation in the superficial laminae of the spinal cord dorsal horn. Our study revealed that this human enzyme hydrolyses opioid peptides belonging to three new groups, endomorphins, hemorphins and exorphins. The enzymatic hydrolysis products of endomorphin-1 were separated and quantified by capillary electrophoresis and the kinetic parameters were determined for human DPP III and rat DPP IV. Both peptidases cleave endomorphin-1 at comparable rates, with liberation of the N-terminal Tyr-Pro. This is the first evidence of DPP III acting as an endomorphin-cleaving enzyme.
二肽基肽酶III（DPP III）是一种锌外肽酶，因其对脑啡肽具有高亲和力且定位于脊髓背角浅层，在哺乳动物疼痛调节系统中可能发挥作用。我们的研究表明，这种人类酶可水解属于三个新组的阿片肽，即内吗啡肽、血啡肽和外啡肽。通过毛细管电泳分离并定量了内吗啡肽-1的酶促水解产物，并测定了人DPP III和大鼠DPP IV的动力学参数。两种肽酶以相当的速率切割内吗啡肽-1，释放出N端的酪氨酸-脯氨酸。这是DPP III作为内吗啡肽切割酶的首个证据。
