Fig. 5. Phosphorylation and stimulation of catalytic activity of cellular p38 following photosensitization with Pd-Bchl-Ser. M2R cells were preincubated with Pd-Bchl-Ser at LD₉₀ and illuminated, and cell lysates were prepared immediately thereafter. (A) Proteins (30 µg protein/lane) were separated by 10% SDS-PAGE and detected with anti-phosphorylated-p38 antibody by immunoblotting. (B) Immunoprecipitation of p38 with anti-phosphorylated p38 was performed using the respective cell lysates. Catalytic activity of p38 was assayed using myelin basic protein (MBP) and [-³²P]ATP as substrates. Lysates were analyzed by autoradiography following SDS-PAGE. Detected bands show ³²P coinciding with position of MBP.