Publications

• Beta-lactamase activity of purified and partially characterized human renal dipeptidase.

  Campbell B.J., Forrester L.J., Zahler W.L., Burks M.

  Human renal dipeptidase has been concentrated from kidneys by homogenization, 1-butanol solubilization, and (NH4)2SO4 fractionation. Final purification was achieved by high-pressure liquid chromatography followed by affinity chromatography. The enzyme appeared to be homogeneous by polyacrylamide g ... >> More

  Human renal dipeptidase has been concentrated from kidneys by homogenization, 1-butanol solubilization, and (NH4)2SO4 fractionation. Final purification was achieved by high-pressure liquid chromatography followed by affinity chromatography. The enzyme appeared to be homogeneous by polyacrylamide gel electrophoresis, and its molecular weight was estimated to be 220,000 by analytical high-pressure liquid chromatography. The molecular weight of human urinary dipeptidase was estimated by agarose gel filtration to be 218,000. Dissociation of human renal dipeptidase in sodium dodecyl sulfate-polyacrylamide gel electrophoresis produced a single polypeptide (Mr 59,000). These results suggest that the native enzyme contains four subunits of Mr 59,000. Analysis of the peptidase for zinc content gave 3.9 g atoms of zinc/mol of enzyme which supports the suggestion of a 4-subunit structure. Carbohydrate analyses of the purified human dipeptidase demonstrated that it was not a glycoprotein, a characteristic that distinguishes it from porcine and rat renal dipeptidase. beta-Lactamase activity of the purified human enzyme was demonstrated by measuring its activity against the two beta-lactam antibiotics, imipenem and SCH 29482. Kinetic analyses indicated that both antibiotics undergo enzyme-catalyzed hydrolysis at rates which could produce inactivation of the antibiotics within the human kidney. The beta-lactamase inhibitor, cilastatin, demonstrated reversible competitive inhibition of the peptidase-catalyzed hydrolysis of both antibiotics with the same Ki of 0.7 microM. << Less

  J. Biol. Chem. 259:14586-14590(1984) [PubMed] [EuropePMC]

• Primary structure of human microsomal dipeptidase deduced from molecular cloning.

  Adachi H., Tawaragi Y., Inuzuka C., Kubota I., Tsujimoto M., Nishihara T., Nakazato H.

  Two cDNA clones corresponding to human microsomal dipeptidase (MDP, formerly referred to as dehydropeptidase-I or renal dipeptidase (EC 3.4.13.11] were isolated from human placental and renal cDNA libraries employing rapid amplification of cDNA ends strategy. The complete amino acid sequence deduc ... >> More

  Two cDNA clones corresponding to human microsomal dipeptidase (MDP, formerly referred to as dehydropeptidase-I or renal dipeptidase (EC 3.4.13.11] were isolated from human placental and renal cDNA libraries employing rapid amplification of cDNA ends strategy. The complete amino acid sequence deduced from the cDNAs contains 411 residues, beginning with a signal peptide of 16 residues. A highly hydrophobic sequence of 16 amino acids is located at the carboxyl terminus, supporting the previous observation which suggested that mature MDP is anchored to the membrane by covalently attached phosphatidylinositol. MDP has four potential N-glycosylation sites and has no apparent sequence similarity to other metallopeptidases. Expression of immunologically cross-reactive and enzymatically active MDP was attained in COS cells transfected with the cDNA. DNA and RNA blot analyses indicated the existence of a single gene and a substantial amount of 1.8-kilobase mRNA in kidney. << Less

  J. Biol. Chem. 265:3992-3995(1990) [PubMed] [EuropePMC]