Cndp1, as known as beta-Ala-His dipeptidase, is a member of the M20 metalloprotease family. In human, this protein is secreted from the liver into the serum. In other mammals, including rodents, it is expressed exclusively within the kidney and lacks a signal peptide. Also, it is a secreted homodimeric dipeptidase that specifically hydrolyzes L-carnosine, and is identified as human carnosinase expressed in the brain. Recombinant mouse Cndp1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.