PURIFICATION AND CHARACTERIZATION OF 2 COLLAGENASE INHIBITORS FROM MOUSE SARCOMA-180 CONDITIONED MEDIUM

We have previously shown that mouse sarcoma 180 cells produce vascular endothelial growth factor [VEGF; Rosenthal et al., 1990, Growth Facto rs, 4: 53-59], an endothelial mitogen that stimulates angiogenesis. Re cent reports have implicated metalloproteinases and their inhibitors i n the regulation of vascular morphogenesis, tumor invasion, and metast asis. We report here that mouse sarcoma 180 cells produce two collagen ase inhibitors. These inhibitors were purified by heparin-Sepharose af finity chromatography, gel filtration, and C4 reverse phase h.p.l.c. A nalytical gel electrophoresis of the purified inhibitors (MS-22 and MS -31) revealed molecular masses of 22,000 and 31,000 Da under reducing conditions, and 20,000 and 30,000 Da under nonreducing conditions, res pectively. The NH2-terminal amino acid sequence of MS-22 was identical to that of tissue inhibitor of metalloproteinases type 2 (TIMP-2) pro duced by human melanoma cells [Stetler-Stevenson et al., 1989, J. Biol . Chem. 264: 17374-17378] over the first 30 amino acids. The NH2-termi nal amino acid sequence of MS-31 was identical to that of murine TIMP- 1 [Gewert et al., 1989, EMBO J 6: 651-657]. Statistical analysis of th e amino acid composition data of these two mouse sarcoma 180-derived c ollagenase inhibitors confirms the identification of MS-22 as TlMP-2 a nd MS-31 as TIMP-1. (C) 1994 Wiley-Liss, Inc.