Identification of an aminopeptidase from the skeletal muscle of grass carp (Ctenopharyngodon idellus).
Fish Physiol Biochem
; 36(4): 953-62, 2010 Dec.
Article
en En
| MEDLINE
| ID: mdl-20020199
ABSTRACT
Aminopeptidases play important roles in turnover of proteins, metabolism of hormones and neurotransmission, cell maturation and immunological regulations. In the present study, an aminopeptidase was purified to homogeneity from the skeletal muscle of grass carp by ammonium sulfate fractionation and sequential chromatographic steps, including DEAE-Sephacel, Sephacryl S-200, hydroxyapatite and Phenyl-Sepharose. The purified enzyme revealed a molecular mass of approximately 105 kDa both on SDS-PAGE and on gel filtration of Superdex 200. The enzymatic activity toward synthetic substrates was optimal at 40°C and pH 7.0-7.5. Metal-chelating agents such as EDTA and EGTA effectively inhibited the enzyme activity while inhibitors to serine, asparatic and cysteine proteinases did not show much effect, suggesting its belonging to metalloproteinase family. A specific aminopeptidase inhibitor bestatin was most effective in suppressing the enzymatic activity and performed in a competitive fashion. The enzymatic activity was slightly enhanced by metal ions of Mg2+ and Mn2+ while inhibited to different extents by Co2+, Cu2+, Zn2+ and Ca2+. Sulfhydryl reagent was necessary to maintain its activity. Purified enzyme demonstrated amidolytic activity most effectively against synthetic aminopeptidase substrate Leu-methylcoumarylamide (MCA) while N-terminal-blocked substrates and myofibrillar proteins were not hydrolyzed. The enzyme purified in the present study was quite possibly a leucine aminopeptidase (LAP) and functions during muscular protein metabolism.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Carpas
/
Músculo Esquelético
/
Leucil Aminopeptidasa
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Fish Physiol Biochem
Año:
2010
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS