Sohár I, Wolz R L, Bond J S
Department of Biochemistry, Virginia Polytechnic and State University, Blacksburg 24061.
Acta Biol Hung. 1991;42(1-3):265-74.
Previously, MMP-7ases were isolated from rat skeletal muscle by gel filtration and anion exchange chromatography. The enzyme that hydrolyzed succinyl-Ala-Ala-Pro-Phe-AMC (AMC: 7-amino-4-methyl-coumarin) was inhibited by EDTA. In this study we attempted to isolate MMP-7ase from mouse kidney. The isolation procedure was the same as that previously used for skeletal muscle. Kidneys of ICR mice were homogenized and, after centrifugation, the supernatant fraction was subjected to gel filtration chromatography. The fraction with the highest activity (Mr 67-72 kDa) was subjected to anion exchange chromatography, which showed three peaks of activity. The second peak hydrolyzed succ-Ala-Ala-Pro-Phe-AMC, but had low activity against Arg- or Ala-AMC. This peak was a single protein (Mr 68-72 kDa) and its activity could be inhibited with EDTA. Several tri- and tetrapeptide derivatives were tested as substrates for this enzyme and the best was found to be succ-Ala-Ala-Pro-Phe-AMC. We can conclude that mouse kidney cytosol contains a metalloendopeptidase similar to muscle MMP-7ase.
此前，通过凝胶过滤和阴离子交换色谱法从大鼠骨骼肌中分离出MMP - 7酶。水解琥珀酰 - 丙氨酸 - 丙氨酸 - 脯氨酸 - 苯丙氨酸 - 7 - 氨基 - 4 - 甲基香豆素（AMC）的酶被EDTA抑制。在本研究中，我们试图从小鼠肾脏中分离MMP - 7酶。分离程序与先前用于骨骼肌的相同。将ICR小鼠的肾脏匀浆，离心后，将上清液部分进行凝胶过滤色谱分析。将活性最高的部分（Mr 67 - 72 kDa）进行阴离子交换色谱分析，显示出三个活性峰。第二个峰水解琥珀酰 - 丙氨酸 - 丙氨酸 - 脯氨酸 - 苯丙氨酸 - AMC，但对精氨酸 - 或丙氨酸 - AMC的活性较低。该峰是单一蛋白质（Mr 68 - 72 kDa），其活性可被EDTA抑制。测试了几种三肽和四肽衍生物作为该酶的底物，发现最佳底物是琥珀酰 - 丙氨酸 - 丙氨酸 - 脯氨酸 - 苯丙氨酸 - AMC。我们可以得出结论，小鼠肾脏胞质溶胶中含有一种类似于肌肉MMP - 7酶的金属内肽酶。
