Figure 1.

Isolation of TIMP, a metanephric mesenchymal growth factor, from medium conditioned by UB cells. Medium conditioned by UB cells was fractionated by heparin-Sepharose chromatography (a). Three peaks of activity were found (100 μg of each fraction was assayed), and fractions 30–40 were pooled and further purified by a Mono Q anion exchanger (b). Active fractions (fractions 42–48; 10 μg of each fraction assayed) were pooled and further purified by phenyl-Sepharose hydrophobic interaction chromatography (c). Activity copurified with a single protein that we purified to homogeneity by Superdex-75 gel filtration (d). In c and d, 10% volume of each fraction was assayed for [³H]thymidine incorporation.