Sequence Identification and Characterization of Human Carnosinase and a Closely Related Non-specific Dipeptidase
Laboratory studyOther animals
- Design
- Laboratory study
- What was measured
- Cloning, tissue expression and enzyme properties of two human genes, CN1 and CN2, expressed as recombinant proteins in Chinese hamster ovary cells.
What the authors reported
CN1 and CN2 encode proteins of 56.8 and 52.7 kDa in the M20 metalloprotease family. Human CN1 mRNA and protein were brain-specific while CN2 was ubiquitous; mouse and rat CN1 orthologues were detectable only in kidney. CN1 was a homodimeric dipeptidase with narrow specificity for Xaa-His dipeptides (carnosine Km 1.2 mM, homocarnosine Km 200 microM), pI 4.5 and maximal activity at pH 8.5, and was identified as human carnosinase. CN2 was not limited to Xaa-His dipeptides, needed Mn2+ for full activity, was inhibited by bestatin (IC50 7 nM), did not degrade homocarnosine and hydrolysed carnosine only at alkaline pH (optimum 9.5); it corresponds to the cytosolic non-specific dipeptidase.
Limits of this study
Recombinant enzyme work; the first molecular identification of the two human carnosinases. Full text not read.
Source
PubMed 12473676 · doi:10.1074/jbc.m209764200
Entry checked against PubMed abstract (E-utilities) on 2026-10-19. The dose shown is the dose the researchers used. It is not a recommendation. How to read this page.