title: Purification and properties of phenylalanyl aminopeptidase synthesised by Pseudomonas sp.
abstract: Intracellular aminopeptidase synthesized by a soil strain of Pseudomonas sp. was purified 323-fold using the following procedure: saturation with ammonium sulfate, separation by preparative electrophoresis, anion-exchange chromatography and gel filtration chromatography. Molecular weight of the enzyme determined according to the latter method was 57 kDa. Aminopeptidase showed a high substrate specificity and affinity to Phe-beta-naphtylamide (Phe-beta-NA) as a substrate. A considerable inhibition of the enzymatic activity by iodoacetamide and p-chloromercuribenzoate (p-CMB) led to the conclusion that it was a cysteine aminopeptidase. Hydrosulphide compounds markedly stabilised the enzyme. Ethylenediaminetetra-acetic acid (EDTA), a metalloenzyme inhibitor, caused a double increase in the phenylalanyl aminopeptidase activity.( )Mg(2+) ions activated the enzyme to a negligible extent, whereas Co(2+), Cu(2+), Cd(2+) and Pb(2+) ions contributed to its inhibition. The highest enzymatic activity was observed at 37 degrees C and pH 7.0.
authors.affiliation: Department of Biochemistry, Warsaw Agricultural University, 02-528 Warsaw, Poland. jankiewecz@delta.sggw.waw.pl
authors.forename: Urszula
authors.initials: U
authors.lastname: Jankiewicz
authors.forename: Wieslaw
authors.initials: W
authors.lastname: Bielawski
mesh_terms: D015081:2-Naphthylamine / Q000378:metabolism; D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D006862:Hydrogen Sulfide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D011480:Protease Inhibitors / Q000494:pharmacology; D011549:Pseudomonas / Q000201:enzymology* / Q000254:growth & development; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D002413:Cations, Divalent; D011480:Protease Inhibitors; D015081:2-Naphthylamine; D000626:Aminopeptidases; C075408:cysteine aminopeptidase; D006862:Hydrogen Sulfide