| Autor: |
G.H. de Haas, D. Raykova, Hubertus M. Verheij, R. Dijkman, H. B. M. Lenting |
| Rok vydání: |
2010 |
| Předmět: |
|
| Zdroj: |
Recueil des Travaux Chimiques des Pays-Bas. 107:202-207 |
| ISSN: |
0165-0513 |
| DOI: |
10.1002/recl.19881070319 |
| Popis: |
The complete amino acid sequence of ovine phospholipase A2 (EC 3.1.1.4) has been determined. The enzyme consists of a single polypeptide chain containing 123 amino acids, crosslinked by seven disulfide bridges, with a molecular weight of 13804. The enzyme differs at six positions from phospholipase A2 isolated from bovine pancreas1. Both enzymes show similar affinities for Ca2+ ions and hydrolyze monomeric substrates with comparable efficiency. Using monomolecular surface films as a substrate, the ovine enzyme was shown to be able to hydrolyze lipids at slightly higher surface pressures than the bovine enzyme. Direct-binding studies showed the higher affinity of the ovine enzyme for micelles of the substrate analogue, n-hexadecylphosphocholine. We suggest that this increased affinity is attributed to a substitution of Asn122 of the bovine enzyme for a tyrosine residue in its ovine counterpart. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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