Figure 3.

SDS-PAGE analysis of proteins at various stages of purification and photoaffinity labeling of CS from the adenosine-agarose fraction. Fractions from each purification step were separated by SDS-PAGE and stained with Coomassie Brilliant Blue. Lane 1, Crude extract (6 μg); lane 2, 50% to 80% saturated (NH₄)₂SO₄ precipitate (23 μg); lane 3, hydroxyapatite (12 μg); lane 4, Shodex anion-exchange chromatography (7.4 μg); lane 5, adenosine-agarose (2.0 μg); and lane 6, Hi-Load adenosine-agarose chromatography (0.7 μg). Lanes 7 and 8, SDS-PAGE after photoaffinity labeling of CS with [methyl-¹⁴C]SAM (1.96 GBq mmol⁻¹). Radioactivity was visualized by an image-analyzer system. Lane 7, With SAH; lane 8, without SAH; lane M, molecular mass marker proteins.