Post-translational processing of Drosophila nucleoside diphosphate kinase.
Publikation/Tidskrift/Serie: Biochem Biophys Res Commun
Förlag: Academic Press
Nucleoside diphosphate kinase (NDPK) was purified from Drosophila melanogaster by a combination of anion-exchange, hydroxyapatite, and reversed-phase chromatography. The identity of the purified enzyme was confirmed by sequencing internal peptides (the N-terminus appeared to be blocked). Post-translational modifications were investigated by using protein chemical and mass spectrometric methods. Analysis by nanoelectrospray ionization-mass spectrometry revealed that the mass of the enzyme was considerably smaller than that predicted from its amino acid sequence. Although its open-reading frame predicts a 153-residue polypeptide, the mature enzyme was found to comprise 152 amino acids, being modified by proteolytic removal of the initiator Met and N-acetylation of Ala2. This explains why the observed pI of the Drosophila enzyme is more acidic than that predicted from its amino acid sequence. No additional post-translational modifications such as glycosylation or O-phosphorylation, which have been identified on homologous NDPKs from other organisms, were detected on the Drosophila enzyme.
- Medicine and Health Sciences
- Drosophila melanogaster : enzymology
- Durapatite : pharmacology
- Nucleoside-Diphosphate Kinase : chemistry
- Nucleoside-Diphosphate Kinase : isolation & purification
- Open Reading Frames
- Peptides : chemistry
- Protein Processing
- Spectrum Analysis
- Ion Exchange
- Biocompatible Materials : pharmacology
- ISSN: 0006-291X