Display options
Cite
Hartmann M, Holm OB, Johansen GA, et al. Mode of action of recombinant Azotobacter vinelandii mannuronan C-5 epimerases AlgE2 and AlgE4. Biopolymers. 2002;63(2):77-88doi: 10.1002/bip.10017.
Hartmann, M., Holm, O. B., Johansen, G. A., Skjåk-Braek, G., & Stokke, B. T. (2002). Mode of action of recombinant Azotobacter vinelandii mannuronan C-5 epimerases AlgE2 and AlgE4. Biopolymers, 63(2), 77-88. https://doi.org/10.1002/bip.10017
Hartmann, Martin, et al. "Mode of action of recombinant Azotobacter vinelandii mannuronan C-5 epimerases AlgE2 and AlgE4." Biopolymers vol. 63,2 (2002): 77-88. doi: https://doi.org/10.1002/bip.10017
Hartmann M, Holm OB, Johansen GA, Skjåk-Braek G, Stokke BT. Mode of action of recombinant Azotobacter vinelandii mannuronan C-5 epimerases AlgE2 and AlgE4. Biopolymers. 2002 Feb;63(2):77-88. doi: 10.1002/bip.10017. PMID: 11786996.
Copy Download .nbib Format: NLM
Share it on

Biopolymers. 2002 Feb;63(2):77-88. doi: 10.1002/bip.10017.

Mode of action of recombinant Azotobacter vinelandii mannuronan C-5 epimerases AlgE2 and AlgE4.

Biopolymers

Martin Hartmann, Olav B Holm, Gunn A B Johansen, Gudmund Skjåk-Braek, Bjørn T Stokke

Affiliations

  1. Norwegian Biopolymer Laboratory, Department of Biotechnology, The Norwegian University of Science and Technology, NTNU, NO-7491 Trondheim, Norway.

PMID: 11786996 DOI: 10.1002/bip.10017

Abstract

The enzymes mannuronan C-5 epimerases catalyze conversion of beta-D-mannuronic acid to alpha-L-guluronic acid in alginates at the polymer level and thereby introduce sequences that have functional properties relevant to gelation. The enzymatic conversion by recombinant mannuronan C-5 epimerases AlgE4 and AlgE2 on alginate type substrates with different degree of polymerization and initial low fraction of alpha-L-guluronic acid was investigated. Essentially no enzymatic activity was found for fractionated mannuronan oligomer substrates with an average degree of polymerization, DP(n), less than or equal 6, whereas increasing the DP(n) yielded increased epimerization activity. This indicates that these enzymes have an active site consisting of binding domains for consecutive residues that requires interaction with 7 or more consecutive residues to show enzymatic activity. The experimentally determined kinetics of the reaction, and the residue sequence arrangement introduced by the epimerization, were modeled using Monte Carlo simulation accounting for the various competing intrachain substrates and assuming either a processive mode of action or preferred attack. The comparison between experimental data and simulation results suggests that epimerization by AlgE4 is best described by a processive mode of action, whereas the mode of action of AlgE2 appears to be more difficult to determine.

Copyright 2002 John Wiley & Sons, Inc.

Substances

MeSH terms

Publication Types