Purification, Characterization, and Cloning of a Cytosolic Aspartyl Aminopeptidase
| Autor: | Sherwin Wilk, Elizabeth Wilk, Ronald P. Magnusson |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Dipeptidyl Peptidase 4
Molecular Sequence Data Biology Glutamyl Aminopeptidase Aminopeptidases Biochemistry Aminopeptidase Homology (biology) Substrate Specificity Mice Cytosol Complementary DNA Escherichia coli Animals Humans Amino Acid Sequence Molecular Biology Peptide sequence Chromatography High Pressure Liquid Gel electrophoresis Base Sequence Molecular mass Brain Cell Biology Molecular biology Molecular Weight Kinetics Glutamyl aminopeptidase Rabbits Aspartyl aminopeptidase |
| Zdroj: | Journal of Biological Chemistry. 273:15961-15970 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.273.26.15961 |
| Popis: | An aminopeptidase with a preference for N-terminal aspartyl and glutamyl residues but distinct from glutamyl aminopeptidase (EC 3.4.11.7) was purified to near homogeneity from rabbit brain cytosol. Its properties were similar to an enzyme described previously (Kelly, J. A., Neidle, E. L., and Neidle, A. (1983) J. Neurochem. 40, 1727–1734). Aspartyl aminopeptidase had barely detectable activity toward simple aminoacyl-naphthylamide substrates. Its activity was determined with the substrate Asp-Ala-Pro-naphthylamide in the presence of excess dipeptidyl-peptidase IV (EC 3.4.14.5). The native enzyme has a molecular mass of 440 kDa and migrates as a single band of 55 kDa after SDS-polyacrylamide gel electrophoresis. The sequences of three tryptic peptides were used to screen the GenBankTM data base of expressed sequence tags. Human and mouse clones described as “similar to a yeast vacuolar aminopeptidase” and containing full-length cDNAs were identified and sequenced. The human cDNA was expressed in Escherichia coli. The amino acid sequence has significant homology to yeast aminopeptidase I, placing it as the first identified mammalian member of the M18 family of metalloproteinases. Homologous sequences in Caenorhabditis elegans and in prokaryotes revealed three conserved histidines, three conserved glutamates and five conserved aspartates. Aspartyl aminopeptidase is found at relatively high levels in all mammalian tissues examined and is likely to play an important role in intracellular protein and peptide metabolism. |
| Databáze: | OpenAIRE |
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