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

Abstract
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.