Olins G M, Spear K L, Siegel N R, Zurcher-Neely H A
Biochim Biophys Acta. 1987 Jul 10;901(1):97-100. doi: 10.1016/0005-2736(87)90260-4.
Atrial natriuretic factor (ANF), a 28-amino-acid peptide secreted from the mammalian heart, is known to be cleared rapidly from the circulation. In vitro and in vivo studies implicate the kidney as an important site for clearance and subsequent degradation of atrial natriuretic factor. We have observed that atrial natriuretic factor is inactivated rapidly by rabbit kidney brush-border membranes. The rate of degradation of ANF measured by the loss of bioactivity followed a similar time-course to the decrease in peptide peak area measured by high-performance liquid chromatography. Interestingly, inactivation of ANF produced only a single major degradation product, which was isolated and purified. Sequence analysis revealed that the product had the same sequence of amino acids as ANF with the Cys-7-Phe-8 bond cleaved and the disulfide bridge between Cys-7 and Cys-23 remaining intact. As the renal brush border contains an abundance of proteolytic activities, it is surprising that this peptide is cleaved primarily at a single peptide bond.
心房利钠因子（ANF）是一种由哺乳动物心脏分泌的含28个氨基酸的肽，已知其能迅速从循环系统中清除。体外和体内研究表明，肾脏是心房利钠因子清除及随后降解的重要部位。我们观察到，心房利钠因子被兔肾刷状缘膜迅速灭活。通过生物活性丧失测定的ANF降解速率与通过高效液相色谱测定的肽峰面积减少遵循相似的时间进程。有趣的是，ANF的失活仅产生一种主要降解产物，该产物被分离和纯化。序列分析表明，该产物与ANF具有相同的氨基酸序列，其中Cys-7-Phe-8键被切断，而Cys-7和Cys-23之间的二硫键保持完整。由于肾刷状缘含有丰富的蛋白水解活性，令人惊讶的是该肽主要在单个肽键处被切割。
