Fig. 4.

HxBP-Rh identifies neprilysin as an MP activity dramatically upregulated in invasive human melanoma cell lines. (A) HxBP-Rh labeling profiles of membrane proteomes from a panel of human melanoma cell lines. An HxBP-Rh-labeled glycoprotein highly up-regulated in invasive melanoma lines (MUM-2B and C-8161) compared with noninvasive melanoma lines (UACC-62, M14-Mel, and MUM-2C) was identified as neprilysin by using a trifunctional HxBP probe (see Methods for more details). Deglycoslyation was accomplished by treating a portion of each HxBP-Rh-labeled proteome with PNGaseF before analysis. (B) Quantitation of neprilysin activity in melanoma membrane proteomes by in-gel fluorescence scanning (n = 3 per group).