IDENTIFICATION AND PARTIAL CHARACTERIZATION OF A METALLOPEPTIDASE FROM PORCINE OVARIES

The follicular fluid of porcine ovaries contains an EDTA-sensitive enz yme activity for the synthetic substrate loxycarbonyl-Val-Lys-Met-4-me thylcoumaryl-7-amide. To investigate its characteristics and its ident ification, the enzyme was partially purified by ammonium sulfate fract ionation followed by column chromatographies on DEAE-Cellulose and che lating Cellulofine columns. The enzyme activity was strongly inhibited by typical chelators, such as EDTA and o-phenanthroline, but after in hibition by EDTA the activity was completely restored with an appropri ate amount of Zn2+ and Co2+ ions. It showed enzyme activity solely for yloxycarbonyl-Val-Lys-Met-4-methylcoumaryl-7-amide among the substrat es tested. The molecular weight of the enzyme was estimated to be 400, 000 by gel filtration. The enzyme activity in the fluid obtained from large follicles of porcine ovaries was significantly higher than that from smaller follicles. It appeared that the granulosa cell extract di d not contain the metalloenzyme activity. Similar enzyme activities we re detected in follicular fluids from bovine and human ovaries. These results suggest that the present enzyme is distinct from any other met alloendopeptidases thus far reported. (C) 1998 Wiley-Liss, Inc.