In vitro translocation of L-alanine:4,5-dioxovalerate transaminase into rat kidney mitochondria.
J Biochem
; 113(5): 557-62, 1993 May.
Article
em En
| MEDLINE
| ID: mdl-7687993
ABSTRACT
A specific rabbit antibody was prepared against rat kidney mitochondrial L-alanine 4,5-dioxovalerate transaminase, which is one of the two enzymes catalyzing the synthesis of delta-aminolevulinic acid in the heme biosynthetic pathway. Total polyadenylated RNA isolated from rat kidney was translated in vitro using rabbit reticulocyte cell-free translation system, and L-alanine4,5-dioxovalerate transaminase was estimated by indirect immunoprecipitation to represent 0.85% of the total translation product. When the total in vitro translated product was incubated with homologous kidney mitochondria, 59% of the [35S]methionine labeled enzyme was translocated into the mitochondria where it was no longer accessible to externally added protease. In relation to total protein translocation, the translocation of L-alanine4,5-dioxovalerate transaminase remained unaltered by addition of hemin up to 50 microM. These results show that, unlike the other enzyme of the heme biosynthetic pathway (delta-aminolevulinic acid synthetase), this enzyme is not under tight control by heme, but nonetheless, functions as an important source to maintain a housekeeping level of delta-aminolevulinic acid.
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Base de dados:
MEDLINE
Assunto principal:
Ácido Aminolevulínico
/
Transaminases
/
Rim
/
Mitocôndrias
Idioma:
En
Ano de publicação:
1993
Tipo de documento:
Article