The umor Necrosis Factor- Converting Enzyme (TACE): A Unique Metal
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- 作者：Mohita J. Mohan ; Theresa Seaton ; Justin Mitchell ; Anne Howe ; Kevin Blackburn ; William Burkhart ; Mary Moyer ; Inder Patel ; Gregory M. Waitt ; J. David Becherer ; Marcia L. Moss ; and Marcos E. Milla
- 刊名：Biochemistry
- 出版年：2002
- 出版时间：July 30, 2002
- 年：2002
- 卷：41
- 期：30
- 页码：9462 - 9469
- 全文大小：85K
- 年卷期：v.41,no.30(July 30, 2002)
- ISSN：1520-4995
文摘
TNF
converting enzyme (TACE) processes precursor TNF between Ala76 and Val77,yielding a correctly processed bioactive 17 kDa protein. Genetic evidence indicates that TACE may alsobe involved in the shedding of other ectodomains. Here we show that native and recombinant forms ofTACE efficiently processed a synthetic substrate corresponding to the TNF cleavage site only. For allother substrates, conversion occurred only at high enzyme concentrations and prolonged reaction times.Often, cleavage under those conditions was accompanied by nonspecific reactions. We also comparedTNF cleavage by TACE to cleavage by those members of the matrix metalloproteinase (MMP) familypreviously implied in TNF release. The specificity constants for TNF cleavage by the MMPs wereapproximately 100-1000-fold slower relative to TACE. MMP 7 also processed precursor TNF at thecorrect cleavage site but did so with a 30-fold lower specificity constant relative to TACE. In contrast,MMP 1 processed precursor TNF between Ala74 and Gln75, in addition to between Ala76 and Val77,while MMP 9 cleaved this natural substrate solely between Ala74 and Gln75. Additionally, the MMPsubstrate Dnp-PChaGC(Me)HK(NMA)-NH2 was not cleaved at all by TACE, while collagenase (
P1), gelatinase (P 9), stromelysin 1 (MMP 3), and matrilysin (MMP 7) all processed this substrateefficiently. All of these results indicate that TACE is unique in terms of its specificity requirements forsubstrate cleavage.
converting enzyme (TACE) processes precursor TNF between Ala76 and Val77,yielding a correctly processed bioactive 17 kDa protein. Genetic evidence indicates that TACE may alsobe involved in the shedding of other ectodomains. Here we show that native and recombinant forms ofTACE efficiently processed a synthetic substrate corresponding to the TNF cleavage site only. For allother substrates, conversion occurred only at high enzyme concentrations and prolonged reaction times.Often, cleavage under those conditions was accompanied by nonspecific reactions. We also comparedTNF cleavage by TACE to cleavage by those members of the matrix metalloproteinase (MMP) familypreviously implied in TNF release. The specificity constants for TNF cleavage by the MMPs wereapproximately 100-1000-fold slower relative to TACE. MMP 7 also processed precursor TNF at thecorrect cleavage site but did so with a 30-fold lower specificity constant relative to TACE. In contrast,MMP 1 processed precursor TNF between Ala74 and Gln75, in addition to between Ala76 and Val77,while MMP 9 cleaved this natural substrate solely between Ala74 and Gln75. Additionally, the MMPsubstrate Dnp-PChaGC(Me)HK(NMA)-NH2 was not cleaved at all by TACE, while collagenase (P1), gelatinase (P 9), stromelysin 1 (MMP 3), and matrilysin (MMP 7) all processed this substrateefficiently. All of these results indicate that TACE is unique in terms of its specificity requirements forsubstrate cleavage.