biostudies-literatureOkumura NJSPS Grant-in-Aids for Scientific Research511-22https://www.ebi.ac.uk/biostudies/studies/S-EPMC4815345biostudies-literatureUnknown25(2)Carnosine dipeptidase II (CN2/CNDP2) is an M20 family metallopeptidase that hydrolyses various dipeptides including β-alanyl-L-histidine (carnosine). Crystallographic analysis showed that CN2 monomer is composed of one catalytic and one dimerization domains, and likely to form homodimer. In this crystal, H228 residue of the dimerization domain interacts with the substrate analogue bestatin on the active site of the dimer counterpart, indicating that H228 is involved in enzymatic reaction. In the present study, the role of intradimer interaction of CN2 in its catalytic activity was investigated using electrospray-ionization time-of-flight mass spectrometry (ESI-TOF MS). First, a dimer interface mutant I319K was prepared and shown to be present as a folded monomer in solution as examined by Protein science : a publication of the Protein SocietyEvidence for an essential role of intradimer interaction in catalytic function of carnosine dipeptidase II using electrospray-ionization mass spectrometry.PMC48153452357016422370040Takao TOkumura NTamura JfalseEvidence for an essential role of intradimer interaction in catalytic function of carnosine dipeptidase II using electrospray-ionization mass spectrometry.Carnosine dipeptidase II (CN2/CNDP2) is an M20 family metallopeptidase that hydrolyses various dipeptides including β-alanyl-L-histidine (carnosine). Crystallographic analysis showed that CN2 monomer is composed of one catalytic and one dimerization domains, and likely to form homodimer. In this crystal, H228 residue of the dimerization domain interacts with the substrate analogue bestatin on the active site of the dimer counterpart, indicating that H228 is involved in enzymatic reaction. In the present study, the role of intradimer interaction of CN2 in its catalytic activity was investigated using electrospray-ionization time-of-flight mass spectrometry (ESI-TOF MS). First, a dimer interface mutant I319K was prepared and shown to be present as a folded monomer in solution as examined by 2016-01-01T00:00:00Z2016 Feb2026-04-14T21:26:03.007Z2019-03-27T03:10:46ZS-EPMC48153452654903710.1002/pro.2842