正常大鼠肾脏分离出的肾小球中存在的一种中性金属蛋白酶对肾小球基底膜的降解作用。

Degradation of glomerular basement membrane by a neutral metalloproteinase(s) present in glomeruli isolated from normal rat kidney.

作者信息

Nguyen H H, Baricos W H, Shah S V

出版信息

Biochem Biophys Res Commun. 1986 Dec 30;141(3):898-903. doi: 10.1016/s0006-291x(86)80127-9.

Abstract

Incubation of glomerular homogenates (200 micrograms protein) with glomerular basement membrane (GBM, 30-35 micrograms hydroxyproline) at pH 7.5 for 36 h at 37 degrees C resulted in significant GBM degradation as measured by hydroxyproline release (40 +/- 6%, n = 17). GBM degradation increased with increasing incubation time (12-48 h) and glomerular protein concentration (50-250 micrograms). GBM degradation was not significantly decreased by inhibitors of serine or cysteine proteinases or the inhibitor of bacterial metalloproteinases, phosphoramidon. In contrast GBM degradation by glomerular homogenates was markedly inhibited by the metal chelators 10mM EDTA (-95 +/- 3%, n = 7) and 2mM 1,10-phenanthroline (-96 +/- 2%, n = 4). Preincubation of glomerular homogenates with trypsin (followed by soya bean trypsin inhibitor) markedly stimulated GBM degradation (+103 +/- 20%, n = 11). These results document the presence of a GBM-degrading, neutral metalloproteinase(s) in glomeruli suggesting an important role for this enzyme in glomerular pathophysiology.

摘要

在37℃、pH 7.5条件下，将肾小球匀浆（200微克蛋白质）与肾小球基底膜（GBM，30 - 35微克羟脯氨酸）一起孵育36小时，结果显示，通过羟脯氨酸释放量测定，GBM出现显著降解（40±6%，n = 17）。GBM降解程度随孵育时间（12 - 48小时）和肾小球蛋白质浓度（50 - 250微克）的增加而增加。丝氨酸或半胱氨酸蛋白酶抑制剂以及细菌金属蛋白酶抑制剂磷酰胺素对GBM降解没有显著降低作用。相反，金属螯合剂10mM EDTA（-95±3%，n = 7）和2mM 1,10 - 菲咯啉（-96±2%，n = 4）可显著抑制肾小球匀浆对GBM的降解。用胰蛋白酶预孵育肾小球匀浆（随后加入大豆胰蛋白酶抑制剂）可显著刺激GBM降解（+103±20%，n = 11）。这些结果证明肾小球中存在一种降解GBM的中性金属蛋白酶，提示该酶在肾小球病理生理学中起重要作用。