Characterization of matrix metalloproteinase in flatfish embryo undergoing formation of lenses.

Members of the matrix metalloproteinase (MMP) family are responsible for breakdown of extracellular matrix components involved in morphogenetic remodeling of animal embryogenesis. The highly sensitive assay of MMP using synthetic fluorescence-quenching substrate was employed to detect and to characterize a veiled MMP activity expressed in Japanese flounder embryos undergoing formation of lenses. The MMP activity was enhanced in proportion to increasing protein amounts of the embryonic lysate over 5 microg, and this reaction was proceeded in a time-dependent manner and with increasing substrate concentrations. Almost 2-fold increase in the embryonic MMP activity occurred by treatment with 4-aminophenylmercuric acetate, but the activity was markedly suppressed by metal chelating reagents. These enzymatic characteristics are apparently consistent with those of mammalian embryonic MMPs, particularly MMP-9. The characterized MMP activity was highly expressed at the specificstage during embryogenesis, indicating that this MMP may be involved in formation of lenses.