Heat-labile bacterial alkaline phosphatase from a marine Vibrio sp

Jónas B. Hauksson, Ólafur S. Andrésson, Bjarni Ásgeirsson*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)

Abstract

Psychrophilic organisms have successfully adapted to various low-temperature environments such as cold ocean waters. Catalysts with increased catalytic efficiencies are produced, generally at the expense of thermal stability due to fewer non-covalent stabilizing interactions. A marine bacterial strain producing a particularly heat-labile alkaline phosphatase was selected from a total of 232 strains isolated from North-Atlantic coastal waters. From partial 16S rRNA sequences the strain was characterized as a Vibrio sp. An alkaline phosphatase was purified 151-fold with 54% yield from the culture medium using a single step affinity chromatography procedure on agarose-linked L-histidyldiazobenzylphosphonic acid. The active enzyme was a 55 ± 6 kDa monomer. The enzyme had optimal activity at pH 10 and was strikingly heat-labile with a half-life of 6 min at 40°C and 30 min at 32°C. This enzyme from Vibrio sp. had a higher turnover number (k(cat)) and higher apparent Michaelis-Menten factor (K(m)) than the enzyme from Escherichia coli, a clear-indication of cold-adaptation. Inorganic phosphate was a competitive inhibitor with a relatively high K(i) value of 1.7 mM. Low affinity for phosphate may contribute to higher turnover rates due to more facile release of product. Copyright (C) 2000 Elsevier Science Inc.

Original languageEnglish
Pages (from-to)66-73
Number of pages8
JournalEnzyme and Microbial Technology
Volume27
Issue number1-2
DOIs
Publication statusPublished - Jul 2000

Bibliographical note

Funding Information:
This work was supported by the Icelandic National Research Council and the University of Iceland Research Fund.

Other keywords

  • Alkaline phosphatase
  • Cold-adaptation
  • Marine bacterium
  • Psychrophilic
  • Stability
  • Vibrio sp

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