FIGURE 2.

Enrichment of ADF activity from HeLa nuclear extracts and proteomics identification of ADF-copurified proteins. A, four-step enrichment scheme. B, ADF activity of Mono S column fractions assayed by EMSA. C, Western blot confirmation of the identity of the proteins that copurified with the ADF activity and were characterized by MALDI-TOF mass spectrometry (MS). The closely migrating hnRNPK bands (noted by arrows) represent post-translationally modified isoforms of hnRNPK. Apparent molecular masses of these isoforms (∼65 kDa) are in agreement with the reported molecular weight of intracellular hnRNPK (44). The third band may be due to a proteolytic fragment of hnRNPK or an unrelated protein. NE, nuclear extract.