DPEP1
Description
The DPEP1 (dipeptidase 1) is a protein-coding gene located on chromosome 16.
Dipeptidase 1 (DPEP1), also known as renal dipeptidase, is a membrane-bound glycoprotein responsible for hydrolyzing dipeptides. It is found in the microsomal fraction of the porcine kidney cortex and exists as a disulfide-linked homodimer that is GPI-anchored to the renal brush border of the kidney. The active site on each homodimer is made up of a barrel subunit with binuclear zinc ions bridged by the Gly125 side-chain located at the bottom of the barrel. The gene coding for DPEP1 is 6 kb long and consists of ten exons and nine introns. The protein itself is made of 411 amino acid residues and is only transcribed in kidney cells. Disulfide linkages in DPEP1 do not contribute to the enzyme's activity but are essential for its proper function because they keep the enzyme's subunits together and attached to the renal brush border. Cysteine 261 is involved in disulfide linkage between the enzyme's subunits and is located close to both the site of the GPI-anchor and the membrane, suggesting its involvement in the enzyme's linkage to the membrane. DPEP1 is a metalloenzyme that specifically uses zinc as its cofactor. The enzyme's typical zinc content is 1.42 ug/mg.
DPEP1 hydrolyzes a wide range of dipeptides, including the conversion of leukotriene D4 to leukotriene E4. It also hydrolyzes cystinyl-bis-glycine (cys-bis-gly) formed during glutathione degradation. Additionally, DPEP1 possesses beta-lactamase activity and can hydrolyze the beta-lactam antibiotic imipenem.
DPEP1 is also known as MBD1, MDP, RDP.
