Production and application of peptidyl-lys metalloendopeptidase: advances, challenges, and future perspectives

Abstract

Peptidyl-lys metalloendopeptidases (PKMs) are enzymes that selectively cleave peptide bonds at the N-terminus of lysine residues present in the P1' position, making them valuable tools in proteomics. This mini-review presents an overview of PKMs, covering their traditional production from native sources, recent advances in recombinant production, and the current limitations in availability. The historical and current applications of PKMs in proteomics are discussed, highlighting their role in protein sequencing, peptide mapping, and mass spectrometry-based studies. Advances in recombinant technology now enable tailored modifications to PKM, allowing it to function not only as a sister enzyme to LysC but also to trypsin, thereby enhancing its suitability for specific analytical applications. The mini-review concludes with a forward-looking statement on PKM research, emphasizing the potential to broaden its use in novel proteomic methods and other applications.

Keywords: Lys-N; MEP; Mass spectrometry; Peptidyl-lys metalloendopeptidase; Proteomics; Trypsin.

Fig. 1

Ribbon model of the PKM from G. frondosa (Hori et al. ; reproduced with permission from the International Union of Crystallography). α-Helices represented in cyan, β-strands in magenta, β-turns in green, and loops in grey. The catalytic zinc ion, two disulfide bridges, and Thr42 with O-linked mannose are illustrated as ball-and-stick models. Colors of atoms are as follows: carbon in black, oxygen in red, sulfur in yellow, and zinc in orange.