カトウ ケイコ   KATO KEIKO
  加藤 啓子
   所属   京都産業大学  生命科学部 先端生命科学科
   職種   教授
期間 2001/05
名称 Serine proteinase inhibitor 3 and murinoglobulin I are potent inhibitors of neuropsin in adult mouse brain
区分 その他
開催場所 AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC JOURNAL OF BIOLOGICAL CHEMISTRY
発表者・共同発表者等 K Kato,T Kishi,T Kamachi,M Akisada,T Oka,R Midorikawa,K Takio,N Dohmae,PI Bird,Sun,JR,F Scott,Y Miyake,K Yamamoto,A Machida,T Tanaka,K Matsumoto,M Shibata,S Shiosaka
発表・展示等 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.
DOI 10.1074/jbc.M010725200