Purification and properties of N-formylmethionine aminopeptidase from rat liver.
A specific enzyme for the liberation of N-terminal N-formylmethionine from N-formylmethionyl peptides was purified 4750-fold from rat liver by successive applications of (NH4)SO4 precipitation, DEAE-cellulose, N-formylbestatin-AH-Sepharose 4B and AH-Sepharose 4B chromatography followed by Sepharose CL-6B gel filtration. The molecular weight was determined by gel filtration on Sepharose CL-6B as 290 000 +/- 5000. This was suggested to be a tetramer consisting of a subunit which was shown by sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis to have a 72 000 +/- 2000 molecular weight. The optimum pH of the enzyme was 7.8. Cd2+ and Hg2+ were highly toxic to the enzyme. Michaelis constants of N-formylmethionyl leucine and N-formylmethionine beta-naphthylamide were 0.03 and 0.2 mM, respectively.
D000626:Aminopeptidases / Q000302:isolation & purification*; D000818:Animals; D002846:Chromatography, Affinity; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D008970:Molecular Weight; D051381:Rats
D000626:Aminopeptidases; C028008:N-formylmethionine aminopeptidase