Purification and characterization of a complex containing matriptase and a Kunitz-type serine protease inhibitor from human milk
Purification and characterization of a complex containing matriptase and a Kunitz-type serine protease inhibitor from human milk
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DOI：
10.1074/jbc.274.26.18237
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发表时间：
1999-06-25
影响因子：
4.8
通讯作者：
Dickson, RB
中科院分区：
文献类型：
--
作者：
Lin, CY;Anders, J;Dickson, RB
间质蛋白酶是一种胰蛋白酶样丝氨酸蛋白酶，具有两个潜在的调节模块（低密度脂蛋白受体和补体C1 r/s结构域），最初从T-47 D乳腺癌细胞中纯化，鉴于其质膜定位，细胞外基质降解活性和乳腺癌细胞的表达，这种蛋白酶可能参与乳腺肿瘤进展的多个方面，包括癌症侵袭。在乳腺癌细胞中，间质蛋白酶主要以未复合的形式检测到;然而，在复合物中检测到低水平的间质蛋白酶。与此形成鲜明对比的是，在人乳中仅检测到复合的间质蛋白酶。复合的间质蛋白酶现已被纯化。从间质蛋白酶相关蛋白获得的氨基酸序列揭示，它们是Kunitz型丝氨酸蛋白酶抑制剂的片段，该抑制剂先前被报道为肝细胞生长因子激活剂的抑制剂。此外，间质蛋白酶及其复合物中检测到乳源性，SV 40 T抗原永生化的乳腺腔上皮细胞系，但不是在人包皮成纤维细胞或HT-1080纤维肉瘤细胞。这些结果表明，乳源性间质蛋白酶复合物可能是由哺乳期乳腺的上皮成分在体内产生的，并且间质蛋白酶的活性和功能可能受到其同源抑制剂的差异调节，将乳腺癌与哺乳期乳腺进行比较。
Matriptase, a trypsin-like serine protease with two potential regulatory modules (low density lipoprotein receptor and complement C1r/s domains), was initially purified from T-47D breast cancer cells, Given its plasma membrane localization, extracellular matrix-degrading activity, and expression by breast cancer cells, this protease may be involved in multiple aspects of breast tumor progression, including cancer invasion. In breast cancer cells, matriptase was detected mainly as an uncomplexed form; however, low levels of matriptase were detected in complexes. In striking contrast, only the complexed matriptase was detected in human milk, The complexed matriptase has now been purified. Amino acid sequences obtained from the matriptase-associated proteins reveal that they are fragments of a Kunitz-type serine protease inhibitor that was previously reported to be an inhibitor of the hepatocyte growth factor activator. In addition, matriptase and its complexes were detected in milk-derived, SV40 T-antigen-immortalized mammary luminal epithelial cell lines, but not in human foreskin fibroblasts or in HT-1080 fibrosarcoma cells. These results suggest that the milk-derived matriptase complexes are likely to be produced by the epithelial components of the lactating mammary gland in vivo and that the activity and function of matriptase may be differentially regulated by its cognate inhibitor, comparing breast cancer with the lactating mammary gland.