MDP1, which is short for nesium-dependent phosphatase 1, is a 176 aa. protein. It has 3 forms by different alternative splicing. This protein belongs to the HAD-like hydrolase superfamily, and usually takes its function with Magnesium. It can be inhibited by vanadate and zinc, and slightly by calcium. MDP1 is a Magnesium-dependent phosphatase which may act as a tyrosine phosphatase.

Dehydropeptidase-I, also known as DPEP1, is a kidney membrane enzyme. Its expression in normal colonic mucosa is very low, but it is highly expressed in colorectal adenoma and cancer specimens and is negatively correlated with parameters of pathological aggressiveness and poor prognosis. The overexpression of DPEP1 suppressed tumor cells invasiveness and increased sensitivity to chemotherapeutic agent Gemcitabine. Growth factor EGF treatment decreased DPEP1 expression. Dehydropeptidase-I may be a candidate target in PDAC for designing improved treatments. It uses zinc as a cofactor and acts as a disulfide-linked homodimer.