A Recombinant Asp-Specific Protease for Bottom-up Mass Spectrometry Workflows

Part # PS303

Abstract

Chris Hosfield¹, Jim Hartnett¹, Alba Katiria González Rivera¹,², Ethan Strauss¹, Sergei Saveliev¹, Michael Rosenblatt¹and Marjeta Urh^1
1Promega Corporation, 2800 Woods Hollow Rd, Madison, WI 53711; ²University of Wisconsin-Madison, Madison, WI.

Bottom-up mass spectrometry workflows typically utilize trypsin to digest proteins into peptides suitable for LC-MS/MS analysis. While trypsin is an excellent protease, alternative proteases are useful for numerous applications including increasing protein sequence coverage and identifying post-translational modifications. LysC, another commonly used protease, is also robust and specific, but has specificity similar to trypsin. Site-specific proteases with orthogonal specificity such as GluC and AspN are useful but can suffer from relatively poor digestion performance. Here we report the expression, purification and characterization of a protease which displays both high cleavage efficiency and a strong preference for cleavage N-terminal to aspartic acid. This new recombinant protease should have broad utility for bottom-up LC-MS/MS workflows.

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