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. 2012 Dec 10;110(1):E15–E22. doi: 10.1073/pnas.1214638110

Fig. 4.

Fig. 4.

The ADP ribosyltransferase assay demonstrates that algal chloroplasts accumulate enzymatically active immunotoxin proteins. Biotinylated NAD+ was mixed with eEF2 and purified αCD22, αCD22PE40, or αCD22CH23PE40. Biotinylated ADP was transferred to eEF2 by enzymatically active exotoxin A. After reaction completion, samples were separated on SDS/PAGE and blotted onto nitrocellulose membranes. An anti-biotin antibody conjugated with alkaline phosphatase was used to detect eEF2 that was ribosylated with ADP-biotin. Western blot demonstrates that αCD22 does not ribosylate eEF2 (lane 1) but that αCD22PE40 (lane 2) and αCD22CH23PE40 (lane 3) have enzymatically active PE40 and do ribosylate eEF2.