Binding of alpha 2-macroglobulin-thrombin complexes and methylamine-treated alpha 2-macroglobulin to human blood monocytes.
Binding of alpha 2-macroglobulin-thrombin complexes and methylamine-treated alpha 2-macroglobulin to human blood monocytes.
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α2-巨球蛋白-凝血酶复合物和甲胺处理的α2-巨球蛋白与人血单核细胞的结合。
DOI：
10.1021/bi00408a033
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发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
Snyderman,R
中科院分区：
文献类型：
--
作者：
Straight,DL;Jakoi,L;McKee,PA;Snyderman,R
1987年12月11日收到的修订版摘要：研究了α 2-巨球蛋白（α 2 M）与人外周血单核细胞的结合。单核细胞是组织巨噬细胞的前体，通过离心淘洗或密度梯度离心从新鲜血液中分离。使用125 I标记的α 2 M进行结合研究。通过快速真空过滤将细胞和结合的配体与游离配体分离。在0 ℃下直接结合研究中获得的数据的非线性最小二乘分析表明，单核细胞以3.0±0.9 nM的K？结合α 2 M-凝血酶复合物，单核细胞具有1545±153个位点/细胞。凝血酶单独没有竞争的网站。结合是二价阳离子依赖性的。直接结合研究还表明，单核细胞以类似于α 2 M-凝血酶的方式结合经甲胺处理的α 2 Min。竞争性结合研究表明，α 2 M-凝血酶和甲胺处理的α 2 M结合到单核细胞上的相同位点。相比之下，天然α 2 M不与α 2 M-凝血酶竞争该位点。在37 ℃下进行的研究表明，结合后，单核细胞内化并降解α 2 M-凝血酶，并排出降解产物。α 2 M-凝血酶复合物的受体周转和降解在用氯喹（一种溶酶体功能抑制剂）处理的单核细胞中被阻断。我们的研究结果表明，人单核细胞对α 2 M-凝血酶和甲胺处理的α 2 M具有二价阳离子依赖性的高亲和力结合位点，该结合位点可能起到从循环中清除α 2 M-蛋白酶复合物的作用。α 2-巨球蛋白（α 2巨球蛋白）是血浆蛋白酶抑制剂，其结合所有四种类型的蛋白水解酶（Barrett & Starkey，1973）。α 2 M-蛋白酶复合物被小鼠组织巨噬细胞结合、内化和降解
Revised Manuscript Received December 11, 1987 abstract: The binding of a2-macroglobulin (a2M) to human peripheral blood monocytes was investigated. Monocytes, the precursors of tissue macrophages, were isolated from fresh blood by centrifugalelutriation or density gradient centrifugation. Binding studies were performed using 125I-labeled a2M. Cells and bound ligand were separated from free ligand by rapid vacuum filtration. Nonlinear least-squares analysis of data obtained in direct binding studies at 0 C showed that monocytes bound the a2M-thrombin complex with a K¿ of 3.0±0.9 nM and the monocyte had 1545±153 sites/cell. Thrombin alone did not compete for the site. Binding was divalent cation dependent. Direct binding studies also demonstrated that monocytes bound methylamine-treated a2Min a manner similar to a2M-thrombin. Competitive binding studies showed that a2M-thrombin and methylamine-treated a2M bound to the same sites on the monocyte. In contrast, native a2M did not compete with a2M-thrombin for the site. Studies done at 37 C suggested that after binding, the monocyte internalized and degraded a2M-thrombin and excreted the degradation products. Receptor turnover and degradation of a2M-thrombin complexes were blocked in monocytes treated with chloroquine, an inhibitor of lysosomal function. Our results indicate that humanmonocytes have a divalent cation dependent, high-affinity binding site for a2M-thrombin and methylamine-treated a2M which may function to clear a2M-proteinase complexes from the circulation. a2-Macroglobulin (a2M)’is a plasma proteinase inhibitor that binds proteolytic enzymes of all four classes (Barrett & Starkey, 1973). a2M-proteinase complexes are bound, internalized, and degraded by tissue macrophages of the mouse
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人血浆 α2-巨球蛋白的物理和化学特性。
影响因子：
4.1
作者：
P. Hall;R. Roberts
通讯作者：
R. Roberts
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
发表时间：
1976
期刊：
Biochimica et Biophysica Acta
影响因子：
--
作者：
M. Debanne;R. Bell;J. Dolovich
通讯作者：
J. Dolovich
巨噬细胞摄取蛋白酶-α-巨球蛋白复合物
DOI：
10.1016/0304-4165(75)90309-8
发表时间：
1975
期刊：
Biochimica et Biophysica Acta
影响因子：
--
作者：
M. Debanne;R. Bell;J. Dolovich
通讯作者：
J. Dolovich
α2-巨球蛋白中烷基胺敏感位点的表征。
DOI：
10.1073/pnas.76.9.4313
发表时间：
1979
影响因子：
11.1
作者：
R. Swenson;J. Howard
通讯作者：
J. Howard
影响因子：
4.1
作者：
BARRETT, AJ;BROWN, MA;SAYERS, CA
通讯作者：
SAYERS, CA