Figure 5.
Partial purification of serum GAPDH. (A) The partial purification of serum GAPDH by DEAE Affigel column chromatography shows the eluted fractions of human serum and the GAPDH activity in respective fractions. Peak 2, representing fractions 17–19, had a higher specific activity of GAPDH, indicating GAPDH purification or isolation. The insert shows immunoblots of fraction 18 that demonstrate the presence of high-molecular-size GAPDH and of multiple proteins under nondenaturing and denaturing conditions, respectively. (B) The silver-stained gel and corresponding immunoblot of eluted fraction 18 (which shows that the majority of silver-stained peptide spots are detected by the FL-GAPDH antibody) indicate the isolation of serum GAPDH by DEAE Affigel and the multimeric subunit composition.