NEB offers several proteases with different recognition sites.

Modified Trypsin (TPCK-treated) (NEB #P8101) selectively cleaves peptide bonds C-terminal to lysine and arginine residues (1). Endoproteinase AspN (NEB #P8104) (flavastacin) and Endoproteinase GluC (NEB #P8100) (Staphylococcus aureus Protease V8) selectively cleave peptide bonds N-terminal to aspartic acid residues and C-terminal to glutamic acid, respectively. These proteases are ideal for proteome analysis by mass spectrophotometry. Proteinase K (NEB #P8102) is a non-specific, subtilisin-related serine protease with a very high specific activity. Furin (NEB #P8077) is a ubiquitous subtilisin-like proprotein convertase with a minimal cleavage site requirement of Arg-X-X-Arg'.

We also offer several proteases with unique, specific recognition sites. Enterokinase (NEB #P8070) is a specific protease that cleaves after lysine at its cleavage site Asp-Asp-Asp-Asp-Lys. Factor Xa (NEB #P8010) cleaves after the arginine residue in its preferred cleavage site Ile-(Glu or Asp)-Gly-Arg.  Genenase™ I (NEB #P8075) is a variant of subtilisin BPN´ that has been engineered to have increased specificity by substituting amino acids in its active site (2,3). NEB recommends using Genenase I to cleave fusion proteins at the site Pro-Gly-Ala-Ala-His-Tyr. These proteases can be used with the pMAL™ protein fusion and purification system (NEB #E8200) during the purification step.

(1) Northrop, J.H. and Kunitz, M. (1931)  Science, 73, 262-263. PMID: 17755302

(2) Carter, P. and Wells, J.A. (1987) Science, 237, 394-399. PMID: 3299704

(3) Carter, P. et al. (1991) Biochemistry, 30, 6142-6148. PMID: 2059622

Genenase™ I is a trademark of Genencor International Inc.
pMAL™ is a trademark of New England Biolabs, Inc.