beta-Ala-His dipeptidase (carnosine dipeptidase 1, CNDP dipeptidase 1, serum carnosinase, glutamate carboxypeptidase-like protein 2, CNDP1, CN1, CPGL2, UNQ1915/PRO4380)

Function

• preferential hydrolysis of beta-Ala-|-His dipeptide (carnosine), & also anserine, Xaa-|-His dipeptides & other dipeptides including homocarnosine

Cofactor: binds 2 Zn+2

Inhibition:

• inhibited by the metal chelator 1,10-o-phenantrolin
• inhibitory concentration 50% (IC(50)) is 5 uM

Kinetic parameters:

• KM=1.27 uM for carnosine
• KM=11.00 uM for carnosine
• KM=0.20 uM for homocarnosine
• KM=1.0 uM for homocarnosine
• Optimum pH is 8.5

Structure

• homodimer
• belongs to the peptidase M20A family

Compartment

secreted

Expression

expressed in adult nervous central system

Pathology

• diabetic patients with the CNDP1 Mannheim allele are less susceptible to nephropathy.
• deficiency of CNDP1 may be the cause of homocarnosinosis

Polymorphism

• number of trinucleotide (CTG) repeat varies among different alleles leading to insertion of Leu residues in signal peptide
• allele with 5 leucines is Mannheim allele

More general terms

• dipeptidase
• glycoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q96KN2.html