Expression of a Biologically Active Murine Tissue Inhibitor of Metalloproteinases‐1 (TIMP‐1) in Baculovirus‐Infected Insect Cells

Murine tissue inhibitor of metalloproteinases-1 (mTIMP-1) was expressed in baculovirus-infected insect cells (Sf9). The protein secreted into the culture medium was purified to homogeneity by means of heparin-Sepharose CL-6B and FPLC. The purified protein showed metalloproteinase-inhibitory activity in two independent assays: reverse zymography and inhibition of collagenase activity. Digestion of the recombinant TIMP-1 with peptide-N-glycanaseF revealed that both N-glycosylation sites are used. 125I-mTIMP-1 intraveneously injected into a male Sprague Dawley rat disappeared within 2 min from the circulation. 5 min after injection more than 50% of the 125I-mTIMP-1 were found in the liver and 20% in the kidneys. At later times, trichloroacetic-acid-soluble material accumulated in the intestinal tract.