caa a22 4500 378874330 CHVBK 20180305123417.0 cr unu---uuuuu 161128e20030220xx s 000 0 eng 10.1515/BC.2003.023 doi (NATIONALLICENCE)gruyter-10.1515/BC.2003.023 Identification of Cytosolic LeucylAminopeptidase (EC 3.4.11.1) as the MajorCysteinylglycine-Hydrolysing Activity in RatLiver [Elektronische Daten] [C. Jösch, L.-O. Klotz, H. Sies] Cysteinylglycine hydrolysis is a step in the metabolism of glutathione and glutathione S-conjugates. We had previously observed that in rat liver the enzymatic activity is predominantly located in the cytosol. Here we demonstrate that cytosolic leucyl aminopeptidase (EC 3.4.11.1) is the major cysteinylglycine hydrolysing activity in rat liver. Evidence was obtained from the use of peptidase inhibitors and from immunoprecipitation studies using Pansorbin-coupled antibodies raised against hog kidney cytosolic leucyl aminopeptidase. Both isolated cytosolic leucyl aminopeptidase and the cysteinylglycine-hydrolysing activity in rat liver cytosol are bound with equal efficiency to the affinity matrix. We demonstrate that cytosolic leucyl aminopeptidase exhibits leucinamidase and cysteinylglycinase activity. Cysteinylglycine, cystinyl-bis-glycine, S-nitrosocysteinylglycine, and bimane-S-cysteinylglycine are hydrolysed at high rates; low activity is seen with leukotriene D4. Our findings establish a previously unrecognised physiological function of cytosolic leucyl aminopeptidase, participating in glutathione metabolism and in the degradation of glutathione S-conjugates via the mercapturic acid pathway. Copyright © 2003 by Walter de Gruyter GmbH & Co. KG Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence Jösch C. aut Klotz L.-O aut Sies H. aut Biological Chemistry Walter de Gruyter 384/2(2003-02-20), 213-218 1431-6730 384:2<213 2003 384 bchm https://doi.org/10.1515/BC.2003.023 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2003.023 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jösch C. aut NATIONALLICENCE 700 1- Klotz L.-O aut NATIONALLICENCE 700 1- Sies H. aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 384/2(2003-02-20), 213-218 1431-6730 384:2<213 2003 384 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter