Basic aminopeptidase from rabbit kidney: purification and partial characterization.
The aminopeptidase activity of a homogenate of rabbit kidney treated with Triton X-100 was measured using L-aminoacyl-2-naphthylamides (AA-NA). After gradient elution ion-exchange chromatography, four peaks of aminopeptidase activity were eluted. The enzyme eluted at 450 microS containing 33.5% of the activity towards Arg-NA was applied to a Superdex 75 column and presented only one protein band on 10% SDS-polyacrylamide gel electrophoresis. This enzyme has an apparent molecular mass of 78 kDa, is five-fold activated by 0.15 M NaCl and the highest Vmax/KM ratio was obtained with Arg-NA. Enzyme activity was inhibited 100% by 0.13 mM sodium p-hydroxymercuribenzoate, 20% by 0.75 mM EDTA and 100% by 0.66 mM o-phenanthroline. Puromycin and bestatin behaved like competitive inhibitors with a Ki of 0.60 mM and 5.0 microM and 5.0 microM, respectively.
Oliveira
S M
SM
Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brasil.
Freitas Júnior
J O
JO
Alves
K B
KB
D015081:2-Naphthylamine / Q000302:isolation & purification*; D000626:Aminopeptidases / Q000302:isolation & purification*; D000818:Animals; D007668:Kidney / Q000737:chemistry*; D011817:Rabbits
D015081:2-Naphthylamine; D000626:Aminopeptidases