Purification and characterization of a novel imidazole dipeptide synthase from the muscle of the Japanese eel Anguilla japonica
Autor: | Hiroki Abe, Shiori Tsubone, Shigeru Okada, Naoko Yoshikawa |
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Rok vydání: | 2007 |
Předmět: |
Dipeptidases
animal structures Physiology Molecular Sequence Data Anserine Carnosine Biochemistry Gel permeation chromatography chemistry.chemical_compound Animals Amino Acid Sequence Japanese eel Peptide Synthases Molecular Biology Edetic Acid chemistry.chemical_classification Chromatography Dipeptide Haptoglobins Sequence Homology Amino Acid Molecular mass biology Chemistry Hydrolysis Muscles Imidazoles Temperature Dipeptides Hydrogen-Ion Concentration Zebrafish Proteins Anguilla biology.organism_classification Amino acid Enzyme Activation Molecular Weight Zinc Enzyme |
Zdroj: | Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. 146:560-567 |
ISSN: | 1096-4959 |
DOI: | 10.1016/j.cbpb.2006.12.002 |
Popis: | We have purified a novel enzyme from eel white muscle which catalyzes the syntheses of imidazole dipeptides, such as carnosine (beta-alanyl-L-histidine), anserine (beta-alanyl-pi-methyl-L-histidine), and balenine (ophidine; beta-alanyl-tau-methyl-L-histidine), directly from their precursors. The enzyme was purified 1130-fold from eel muscle by a series of column chromatographies. Although eel muscle contains a large amount of carnosine and only trace amounts of anserine and balenine, the anserine synthesizing activity was by far the highest. From gel permeation chromatography, the molecular mass of the enzyme was calculated to be 275kDa. SDS-PAGE of the purified enzyme represented a band around 43kDa, suggesting that the native enzyme is a hexamer or heptamer. The optimal pH and temperature were around 9.5 and 60 degrees C, respectively. K(m) values for beta-alanine and pi-methyl-L-histidine were 44 and 89mM, respectively. The enzyme was greatly activated by Zn(2+) and inhibited by EDTA. The N-terminal amino acid sequence of 25 residues of the purified enzyme showed 52% amino acid identity to 38-62 residues of zebrafish haptoglobin precursor. The purified enzyme also exhibited hydrolytic activity against these imidazole dipeptides. |
Databáze: | OpenAIRE |
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