Fig. 3

FPLC purification of type II human recombinant procollagen from HT1080 cell line. a Western blot for type II collagen of samples eluting from the Q-sepharose column. Samples were eluted in Q sepharose buffer plus a step gradient of NaCl as indicated. Numbers at the top the lanes refer to the fraction collected, and samples are loaded in equal volumes into each lane of the gel. The earliest fractions contain the most procollagen; this decreases with increasing ionic strength. b Coomassie-stained gel showing pooled fractions 1–4 (left lane) and a molecular weight marker (right lane). The two bands of highest molecular weights are full-length type II procollagen pro-α chains, presumably with different internal crosslinking in the propeptides (see text)