Disease relevance of Dpp3

• Each mutated cDNA was expressed in E. coli (BL21), and each expressed DPP III was purified to apparent homogeneity on SDS-polyacrylamide gel electrophoresis [1].

High impact information on Dpp3

• Dipeptidyl-aminopeptidase III of rat brain. Selective affinity for enkephalin and angiotensin [2].
• The recoveries of the enzyme activities by the addition of various metal ions to apo-DPP III were also measured, and Co(2+), Ni(2+), and Cu(2+) ions completely recovered the enzyme activities as did Zn(2+) [3].
• All of these data suggest that the donor set and the coordination geometry of the metal ions in DPP III, which has the HExxxH motif as the metal binding site, are very similar to those of the metal ions in thermolysin, which has the HExxH motif [3].
• The role of the HELLGH (residues 450-455) motif in the sequence of rat dipeptidyl peptidase III (EC 3.4.14.4) was investigated by replacing Glu451 with an alanine or an aspartic acid residue and by replacing His450 and His455 with a tyrosine residue by site-directed mutagenesis [4].
• Arylamidase, dipeptidyl peptidase III and most of the leucine aminopeptidase could be extracted from the muscle with a neutral salt solution, but dipeptidyl peptidase I was extracted only in the presence of Triton X-100; dipeptidyl peptidase II showed an intermediate extraction behaviour [5].

Biological context of Dpp3

• For further information on the molecular structure, we screened a rat liver cDNA library using affinity-purified anti-rat DPP III rabbit IgG antibodies, determined the cDNA structure and deduced the amino acid sequence [6].
• Furthermore, we screened a rat liver cDNA library using affinity-purified anti-rat DPP III rabbit IgG, and we determined the cDNA structure and deduced the amino acid sequence [7].

Anatomical context of Dpp3

• A search of databases revealed a high similarity between the human erythrocyte and rat liver DPP III: 21 matches out of 34 detected peptides were found, covering 40% of the total sequence [8].
• The DPP III antigen was detected in significant amounts in the cytosol of various rat tissues by immunohistochemical examination [6].

Associations of Dpp3 with chemical compounds

• To comprehend the importance of cysteine residues for the regulation of enzyme activity, we replaced each of seven cysteine residues in rat dipeptidyl peptidase III cDNA with alanine, glycine, or glutamic acid residue using site-directed mutagenesis [1].
• Furthermore, both Cys(176) --> Gly and Cys(176) --> Glu mutated enzymes showed no DPP III activity [1].
• Among numerous biologically active peptides tested, angiotensins and enkephalins were the most preferred substrates with micromolar affinities, suggesting that dipeptidyl-aminopeptidase III may play a physiologic role in regulating enkephalin and/or angiotensin disposition [2].
• DPP III was potently inhibited by EDTA, 1,10-phenanthroline, DFP, PCMBS and NEM [6].
• These findings suggest that DPP III is an exo-type peptidase with characteristics of a metallo- and serine peptidase [6].

Analytical, diagnostic and therapeutic context of Dpp3

• Dipeptidyl peptidase III from rat liver cytosol: purification, molecular cloning and immunohistochemical localization [6].

References