| Autor: |
Becker, Christoph, Kruse, Markus-N., Slotty, Kristina A., Köhler, Danny, Harris, J. Robin, Rösmann, Sandra, Sterchi, Erwin E., Stöcker, Walter |
| Předmět: |
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| Zdroj: |
Biological Chemistry; May2003, Vol. 384 Issue 5, p825-831, 7p, 1 Black and White Photograph, 2 Diagrams, 3 Graphs |
| Abstrakt: |
Meprins are zinc-endopeptidases of the astacin family, which are expressed as membrane-bound or secreted forms in renal and intestinal brush-border membranes of mouse, rat and man. There are two types of meprin subunits, α and β, which form disulfide-bonded homo- and heterodimers; further oligomerization is mediated by non-covalent interactions. Both subunits are translated as proenzymes that have to be activated by removal of an N-terminal propeptide. In the gut, the most probable activator is trypsin. In addition, plasmin has been shown to activate the human α subunit in colorectal cancer tissue. In the present study we have overexpressed the human meprin α subunit and a His-tagged soluble tail-switch-mutant of meprin β in Baculovirus-infected insect cells. The recombinant homo-oligomeric proteins were purified by gel filtration and affinity chromatography with yields of up to 10 mg/l cell culture medium and analyzed with regard to their activation mechanism. While both α and Β homo-oligomers are activated by trypsin, only meprin α homo-oligomers are processed to their mature form by plasmin. These results indicate a different accessibility of the propeptide in meprin homo-oligomers and suggest an explanation for the appearance of meprin hetero-oligomers consisting of active α, but latent β subunits. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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