Prolyl aminopeptidase from rat brain and kidney

Abstract

Based on the liberation of proline from ProLeuGlyNH2 (MIF-1, melanostatin) manganese-activated prolyl aminopeptidase activities were purified from rat brain and kidney cytosolic fractions. They were distinguished from other di-and tripeptidases and an arylamidase liberdting N-terminal proline. Purified prolyl aminopeptidase from both sources had identical molecular properties (native M , 300000, subunit M , 54000) and very similar catalytic properties. The action of the purified enzymes was not restricted to proline. Other, in particular lipophilic, amino acids were cleaved from di-, tri-and oligopeptides with even higher velocities. Peptides with N-terminal penultimate proline residues were not degraded. From a comparison of molecular data, action on peptides, influence of pH values, inhibitors and activators, it is concluded that the activity is identical with leucyl aminopeptidase (EC 3.4.11.1) and that a separate prolyl aminopeptidase (EC 3.4.11.5) does not exist in rats.

Crystallization and preliminary X‐ray diffraction analysis of proline iminopeptidase from Xanthomonas campestris pv. citri

“…However, this enzyme has been found mainly in bacteria [4][5][6][7][8][9][10][11][12] and in some plants [13]. The failure to isolate the enzyme from mammalian tissues, together with the fact that other aminopeptidases like leucine aminopeptidase [14] and even carboxylesterases [15,16] have a weak activity on the amide substrate used in the proline iminopeptidase assay, suggests the absence of a true PIP activity in the latter sources.…”

Hydrolysis of S-aryl-cysteinylglycine conjugates catalyzed by porcine kidney cortex membrane dipeptidase

“…Prolyl aminopeptidase activity was determined with a ninhydrin colorimetric assay specific for the release of proline (Messer, 1961). It was shown that mammalian prolyl aminopeptidase, in addition to removing N-terminal proline, also liberates other, more lipophilic amino acids from di-, tri-and oligopeptides (Turzynski and Mentlein, 1990). It was concluded that the mammalian prolyl aminopeptidase is likely identical to leucyl aminopeptidase, at least in rats, based on several lines of evidence including a comparison of their molecular data, co-purification on ion-exchange chromatography, actions on various peptides, and similar responses to inhibitors and activators.…”

“…3.4.11.1) (Cappiello et al, 2004;Jösch et al, 1998;Jösch et al, 2003), and prolyl aminopeptidase (also known as cytosol aminopeptidase V; E.C. 3.4.11.5) (Turzynski and Mentlein, 1990). The relative roles of these enzymes in the metabolism of xenobiotics are still unclear.…”

“…It was unclear whether mammalian prolyl aminopeptidase is only specific for peptides containing an N-terminal proline or whether it represents an aminopeptidase with broader substrate specificity. Rat brain and kidney cytosolic prolyl aminopeptidase were purified and separated from other di-and tripeptidases with DEAESephacel, prolylleucylglycine (PLG)-Sepharose, Sephacryl S-300, and Mono Q columns (Turzynski and Mentlein, 1990). Prolyl aminopeptidase activity was determined with a ninhydrin colorimetric assay specific for the release of proline (Messer, 1961).…”

Cloning, sequencing, and high expression of the proline iminopeptidase gene from Bacillus coagulans

“…However, the presence of a real proline iminopeptidase in mammalian tissues has remained uncertain, since other aminopeptidases like leucine aminopeptidase (32), and even carboxylesterases (8,16) Replacement of the TTG initiation codon with an ATG codon by the insertion of an adaptor (Fig. 1).…”