caa a22 4500 477105351 CHVBK 20180405111552.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF01570145 doi (NATIONALLICENCE)springer-10.1007/BF01570145 Purification and properties of an intracellular leucine aminopeptidase from the fungus, Penicillium citrinum strain IFO 6352 [Elektronische Daten] [S Kwon, S Park, J Cho] An intracellular leucine aminopeptidase (LAP) fromPenicillium citrinum (IFO 6352) was purified to homogeneity using three successive purification steps. The enzyme has a native molecular mass of 63 kDa using HPLC gel filtration analysis and a molecular mass of 65 kDa when using SDS-polyacrylamide gel electrophoresis. This monomeric aminopeptidase showed maximum enzyme activity at pH 8.5. An optimum temperature was 45-50°C whenl-Leu-p-nitroanilide (pNA) was the substrate, and enzyme activity drastically decreased above 60°C. The Michaelis-Menten constants forl-Leu-pNA andl-Met-pNA were 2.7 mM and 1.8 mM, respectively. When the enzyme reacted with biosynthetic methionyl human growth hormone, it showed high specificity for N-terminal methionine residue and recognized a stop sequence (Xaa-Pro). The aminopeptidase was inactivated by EDTA or 1,10-phenanthroline, indicating that it is a metallo-exoprotease. Enzyme activity was restored to 90% of maximal activity by addition of Co2+ ions. The activity of EDTA-treated enzyme was restored by addition of Zn2+, but reconstitution with Ca2+, Mg2+ or Mn2+ restored some enzyme activity. It is likely that Co2+ ions play an important role in the catalysis or stability of thePenicillium citrinum aminopeptidase, as zinc plays a similar function in other leucine aminopeptidases. Society for Industrial Microbiology, 1996 leucine aminopeptidase nationallicence Penicilium citrinum nationallicence methionine removal nationallicence Kwon S. Biotech Research Institute, LG Chem Research Park, PO Box 61, 305-600, Dae Jeon, Korea aut Park S. Biotech Research Institute, LG Chem Research Park, PO Box 61, 305-600, Dae Jeon, Korea aut Cho J. Biotech Research Institute, LG Chem Research Park, PO Box 61, 305-600, Dae Jeon, Korea aut Journal of Industrial Microbiology Springer-Verlag 17/1(1996-07-01), 30-35 0169-4146 17:1<30 1996 17 10295 https://doi.org/10.1007/BF01570145 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01570145 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kwon S. Biotech Research Institute, LG Chem Research Park, PO Box 61, 305-600, Dae Jeon, Korea aut NATIONALLICENCE 700 1- Park S. Biotech Research Institute, LG Chem Research Park, PO Box 61, 305-600, Dae Jeon, Korea aut NATIONALLICENCE 700 1- Cho J. Biotech Research Institute, LG Chem Research Park, PO Box 61, 305-600, Dae Jeon, Korea aut NATIONALLICENCE 773 0- Journal of Industrial Microbiology Springer-Verlag 17/1(1996-07-01), 30-35 0169-4146 17:1<30 1996 17 10295 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer