Characteristics of the macrophage uptake of proteinase-α-macroglobulin complexes☆
Characteristics of the macrophage uptake of proteinase-α-macroglobulin complexes☆
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巨噬细胞摄取蛋白酶-α-巨球蛋白复合物的特性☆
DOI：
10.1016/0304-4165(76)90055-6
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
J. Dolovich
中科院分区：
文献类型：
--
作者：
M. Debanne;R. Bell;J. Dolovich
标记的蛋白水解酶（胰蛋白酶、亚替洛肽酶A）与血浆α-巨球蛋白之间形成的复合物被兔肺泡巨噬细胞迅速、选择性地吸收。吸收发生在ph的一个狭窄区域内。吸收动力学受温度影响；特别是，巨噬细胞在37°C下孵育后，加入标记的复合物会降低其吸收复合物的能力。EDTA阻止标记复合物与巨噬细胞的结合，并能解离先前结合的标签。EDTA的作用可以通过加入钙或镁或两者同时加入而逆转。碘乙酰胺不阻止复合物的更新，但使它们仍然可以通过EDTA与细胞分离。巨噬细胞复合物在37℃无碘乙酰胺条件下孵育，上清液中出现三氯乙酸溶酶产物。这些观察结果表明，兔肺泡巨噬细胞对蛋白酶-α-巨糖蛋白复合物的选择性摄取可分为三个阶段：(1)依赖于二价阳离子且pH敏感的膜结合阶段；(2)碘乙酰胺抑制的内吞作用阶段；(3)所含标记酶的温度依赖性水解阶段。
Complexes formed between labelled proteolytic enzymes (trypsin, subtilopeptidase A) and the α-macroglobulins of plasma are rapidly and selectively taken up by rabbit alveolar macrophages. The uptake occurs oxver a narrow zone of pH. Kinetics of the uptake is affected by temperature; in particular, incubation of macrophages at 37° C before the addition of labeled complex reduces the capacity to take up complexes. EDTA prevents the association of labelled complexes with macrophages, and can dissociate previously bound label. The effect of EDTA is reversed by the addition of calcium or magnesium or both. Iodoacetamide does not prevent the uptale of complexes but causes them to remain available for dissociation from the cells by EDTA. Incubation of complexes with macrophages at 37° C with no iodoacetamide results in the appearance of trichloroacetic acid soluble products of the enzyme in the supernatant fluid. These observations indicate that the selective uptake of proteinase-α-macroglubin complexes with rabbit alveolar macrophages can be resolved into three phases: (1) membrane binding which depends upon divalent cations and is pH sensitive, (2) endocytosis inhibitable by iodoacetamide and (3) temperature-dependent hydrolysis of the contained labelled enzyme.