Figure 3.

Aminopeptidase activity of C. elegans-expressed recombinant H11 proteins. (A) Aminopeptidase activity of rH11 proteins was measured as the change in absorbance at 405 nm using l-leucine p-nitroanilide as substrate. Activity was measured at pH5.5 (striped bars) and pH7 (blue bars) for singly expressed rH11 proteins, rH11-4 and rH11-5 co-expressed in C. elegans (rH11-4/5) and native H11-enriched extract. 500 ng total protein was added per assay. The results of triplicate assays are shown with error bars representing the standard error. (B) Reduction in aminopeptidase (AP) activity of rH11-4/5 co-expressed proteins (striped bars) and native H11 extract (blue bars) was measured in the presence of amastatin or bestatin, both at 10 μM final concentration. Assays were carried out in duplicate and % reduction calculated relative to pre-incubation in buffer alone.