AlgE4 is a mannuronan C5 epimerase converting homopolymeric sequences
of mannuronate residues in alginates into mannuronate/guluronate
alternating sequences. Treating alginates of different biological
origin with AlgE4 resulted in different amounts of alternating sequences.
Both ionically cross-linked alginate gels as well as alginic acid
gels were prepared from the epimerised alginates. Gelling kinetics
and gel equilibrium properties were recorded and compared to results
obtained with the original non-epimerised alginates. An observed
reduced elasticity of the alginic acid gels following epimerisation
by AlgE4 seems to be explained by the generally increased acid solubility
of the alternating sequences. Ionically (Ca2+) cross-linked gels
made from epimerised alginates expressed a higher degree of syneresis
compared to the native samples. An increase in the modulus of elasticity
was observed in calcium saturated (diffusion set) gels whereas calcium
limited, internally set alginate gels showed no change in elasticity.
An increase in the sol-gel transitional rate of gels made from epimerised
alginates was also observed. These results suggest an increased possibility
of creating new junction zones in the epimerised alginate gel due
to the increased mobility in the alginate chain segments caused by
the less extended alternating sequences. (C) 2000 Elsevier Science
B.V. All rights reserved.
%0 Journal Article
%1 Draget2000a
%A Draget, K. I.
%A Strand, B.
%A Hartmann, M.
%A Valla, S.
%A Smidsrod, O.
%A Skjak-Braek, G.
%C PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
%D 2000
%I ELSEVIER SCIENCE BV
%J Int. J. Biol. Macromol.
%K ; ;; [ISI:] alginate; beads chains; chemical-composition; epimerase; extension; formation gel gelling mannuronan properties; residues; sequence; uronate
%N 2
%P 117 -- 122
%T Ionic and acid gel formation of epimerised alginates; the effect
of AlgE4
%V 27
%X AlgE4 is a mannuronan C5 epimerase converting homopolymeric sequences
of mannuronate residues in alginates into mannuronate/guluronate
alternating sequences. Treating alginates of different biological
origin with AlgE4 resulted in different amounts of alternating sequences.
Both ionically cross-linked alginate gels as well as alginic acid
gels were prepared from the epimerised alginates. Gelling kinetics
and gel equilibrium properties were recorded and compared to results
obtained with the original non-epimerised alginates. An observed
reduced elasticity of the alginic acid gels following epimerisation
by AlgE4 seems to be explained by the generally increased acid solubility
of the alternating sequences. Ionically (Ca2+) cross-linked gels
made from epimerised alginates expressed a higher degree of syneresis
compared to the native samples. An increase in the modulus of elasticity
was observed in calcium saturated (diffusion set) gels whereas calcium
limited, internally set alginate gels showed no change in elasticity.
An increase in the sol-gel transitional rate of gels made from epimerised
alginates was also observed. These results suggest an increased possibility
of creating new junction zones in the epimerised alginate gel due
to the increased mobility in the alginate chain segments caused by
the less extended alternating sequences. (C) 2000 Elsevier Science
B.V. All rights reserved.
@article{Draget2000a,
__markedentry = {[phpts:6]},
abstract = {AlgE4 is a mannuronan C5 epimerase converting homopolymeric sequences
of mannuronate residues in alginates into mannuronate/guluronate
alternating sequences. Treating alginates of different biological
origin with AlgE4 resulted in different amounts of alternating sequences.
Both ionically cross-linked alginate gels as well as alginic acid
gels were prepared from the epimerised alginates. Gelling kinetics
and gel equilibrium properties were recorded and compared to results
obtained with the original non-epimerised alginates. An observed
reduced elasticity of the alginic acid gels following epimerisation
by AlgE4 seems to be explained by the generally increased acid solubility
of the alternating sequences. Ionically (Ca2+) cross-linked gels
made from epimerised alginates expressed a higher degree of syneresis
compared to the native samples. An increase in the modulus of elasticity
was observed in calcium saturated (diffusion set) gels whereas calcium
limited, internally set alginate gels showed no change in elasticity.
An increase in the sol-gel transitional rate of gels made from epimerised
alginates was also observed. These results suggest an increased possibility
of creating new junction zones in the epimerised alginate gel due
to the increased mobility in the alginate chain segments caused by
the less extended alternating sequences. (C) 2000 Elsevier Science
B.V. All rights reserved.},
added-at = {2011-11-04T13:47:04.000+0100},
address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
author = {Draget, K. I. and Strand, B. and Hartmann, M. and Valla, S. and Smidsrod, O. and Skjak-Braek, G.},
authoraddress = {Norwegian Univ Sci & Technol, Dept Biotechnol, Norwegian Biopolymer
Lab, N-7491 Trondheim, Norway. ; Norwegian Univ Sci & Technol, Dept
Biotechnol, UNIGEN Ctr Mol Biol, N-7489 Trondheim, Norway.},
biburl = {https://www.bibsonomy.org/bibtex/2a42e95a43aa00a4e9ab6b479a2390670/pawelsikorski},
citedref = {ANDRESEN IL, 1977, CARBOHYD RES, V58, P271 ; DRAGET KI, 1991, CARBOHYD
POLYM, V14, P159 ; DRAGET KI, 1994, CARBOHYD POLYM, V25, P31 ; DRAGET
KI, 1996, CARBOHYD POLYM, V29, P209 ; GRASDALEN H, 1977, CARBOHYD
RES, V56, C11 ; GRASDALEN H, 1979, CARBOHYD RES, V68, P23 ; GRASDALEN
H, 1983, CARBOHYD RES, V118, P255 ; HAUG A, 1963, ACTA CHEM SCAND,
V17, P1653 ; HAUG A, 1967, ACTA CHEM SCAND, V21, P768 ; HOIDAL HK,
1999, J BIOL CHEM, V274, P12316 ; LARSEN B, 1969, ACTA CHEM SCAND,
V23, P355 ; MARTINSEN A, 1989, BIOTECHNOL BIOENG, V33, P79 ; RAMSTAD
MV, 1999, ENZYME MICROB TECH, V24, P636 ; SKJAKBRAEK G, 1989, CARBOHYD
POLYM, V10, P31 ; SMIDSROD O, 1969, MACROMOLECULES, V2, P42 ; SMIDSROD
O, 1972, ACTA CHEM SCAND, P26 ; SMIDSROD O, 1972, ACTA CHEM SCAND,
V26, P71 ; SMIDSROD O, 1973, CARBOHYD RES, V27, P107 ; SMIDSROD O,
1974, FARADAY DISCUSS, V57, P263 ; SMIDSROD O, 1996, CARBOHYDR EUR,
V14, P6 ; SMIDSROD O, 1996, FOOD COLLOIDS PROTEI, P279 ; STOKKE BT,
1991, MACROMOLECULES, V24, P4637 ; STOKKE BT, 1993, CARBOHYD POLYM,
V21, P39 ; STOKKE BT, 1993, CARBOHYD POLYM, V22, P57 ; VALLA S, 1996,
CARBOHYDR EUR, V14, P14 ; WHITTINGTON SG, 1971, BIOPOLYMERS, V10,
P1481},
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intrahash = {a42e95a43aa00a4e9ab6b479a2390670},
isifile-dt = {Article},
isifile-ga = {310UG},
isifile-j9 = {INT J BIOL MACROMOL},
isifile-nr = {26},
isifile-pi = {AMSTERDAM},
isifile-rp = {Draget, KI, Norwegian Univ Sci & Technol, Dept Biotechnol, Norwegian
; Biopolymer Lab, N-7491 Trondheim, Norway.},
isifile-sc = {Biochemistry & Molecular Biology},
isifile-tc = {15},
issn = {0141-8130},
journal = {Int. J. Biol. Macromol.},
keywords = {; ;; [ISI:] alginate; beads chains; chemical-composition; epimerase; extension; formation gel gelling mannuronan properties; residues; sequence; uronate},
language = {English},
month = {APR 12},
number = 2,
owner = {phpts},
pages = {117 -- 122},
publisher = {ELSEVIER SCIENCE BV},
size = {6 p.},
sourceid = {ISI:000086845700002},
timestamp = {2011-11-04T13:47:09.000+0100},
title = {Ionic and acid gel formation of epimerised alginates; the effect
of AlgE4},
volume = 27,
year = 2000
}