Serine proteinase inhibitor 3 and murinoglobulin I are potent inhibitors of neuropsin in adult mouse brain
Serine proteinase inhibitor 3 and murinoglobulin I are potent inhibitors of neuropsin in adult mouse brain
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DOI：
10.1074/jbc.m010725200
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发表时间：
2001-05-04
影响因子：
4.8
通讯作者：
Shiosaka, S
中科院分区：
文献类型：
--
作者：
Kato, K;Kishi, T;Shiosaka, S
细胞外丝氨酸蛋白酶neuropsin（NP）在成年人大脑的前脑边缘区表达，并与突触可塑性有关。我们筛选内源性NP抑制剂与重组NP（r-NP）从成年小鼠大脑的海马和大脑皮层的提取物。检测到两个SDS稳定的复合物，并在其纯化后，通过氨基酸测序和质谱法确定肽序列，显示靶分子是丝氨酸蛋白酶抑制剂3（SPI 3）和鼠源性蛋白酶I（MUG I）。将重组SPI 3加入到r-NP中产生SDS稳定的复合物，复合物的形成遵循双分子动力学，缔合速率常数为3.4 +/- 0.22 × 10（6）M-（1）s（-1），表明SPI 3是NP的缓慢、紧密结合抑制剂，原位杂交组织化学结果显示，SPI 3 mRNA在海马CA 1-CA 3区锥体神经元表达，NP mRNA也有表达。当r-NP/MUG I摩尔比为1：2时，MUG I可抑制r-NP对纤维连接蛋白的降解，抑制率为24%。免疫荧光组织化学显示MUG I定位于海马神经元。这些结果表明，SPI 3和MUG I分别用于抑制NP和控制成年脑中NP的水平。
Extracellular serine protease neuropsin (NP) is expressed in the forebrain limbic area of adult brain and is implicated in synaptic plasticity. We screened for endogenous NP inhibitors with recombinant NP (r-NP) from extracts of the hippocampus and the cerebral cortex in adult mouse brain. Two SDS-stable complexes were detected, and after their purification, peptide sequences were determined by amino acid sequencing and mass spectrometry, revealing that target molecules were serine proteinase inhibitor-3 (SPI3) and murinoglobulin I (MUG I). The addition of the recombinant SPI3 to r-NP resulted in an SDS-stable complex, and the complex formation followed bimolecular kinetics with an association rate constant of 3.4 +/- 0.22 x 10(6) M-(1) s(-1), showing that SPI3 was a slow, tight binding inhibitor of NP, In situ hybridization histochemistry showed that SPI3 mRNA was expressed in pyramidal neurons in the hippocampal CA1-CA3 subfields, as was NP mRNA. Alternatively, the addition of purified plasma MUG I to r-NP resulted in an SDS-stable complex, and MUG I inhibited degradation of fibronectin by r-NP to 24% at a r-NP/MUG I molar ratio of 1:2, Immunofluorescence histochemistry showed that MUG I localized in the hippocampal neurons. These findings indicate that SPI3 and MUG I serve to inactivate NP and control the level of NP in adult brain, respectively.