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Probing stability of the modular thermostable xylanase Xyn10A,

Abou-Hachem, Maher LU ; Olsson, Fredrik LU and Nordberg Karlsson, Eva LU (2003) In Extremophiles 7(6). p.483-491
Abstract
The thermophilic bacterium Rhodothermus marinus produces a modular xylanase (Xyn10A) consisting of two N-terminal carbohydrate-binding modules (CBMs), followed by a domain of unknown function, and a catalytic module flanked by a fifth domain. Both Xyn10A CBMs bind calcium ions, and this study explores the effect of these ions on the stability of the full-length enzyme. Xyn10A and truncated forms thereof were produced and their thermostabilities were evaluated under different calcium loads. Studies performed using differential scanning calorimetry showed that the unfolding temperature of the Xyn10A was significantly dependent on the presence of Ca2+, and that the third domain of the enzyme binds at least one Ca2+. Thermal inactivation... (More)
The thermophilic bacterium Rhodothermus marinus produces a modular xylanase (Xyn10A) consisting of two N-terminal carbohydrate-binding modules (CBMs), followed by a domain of unknown function, and a catalytic module flanked by a fifth domain. Both Xyn10A CBMs bind calcium ions, and this study explores the effect of these ions on the stability of the full-length enzyme. Xyn10A and truncated forms thereof were produced and their thermostabilities were evaluated under different calcium loads. Studies performed using differential scanning calorimetry showed that the unfolding temperature of the Xyn10A was significantly dependent on the presence of Ca2+, and that the third domain of the enzyme binds at least one Ca2+. Thermal inactivation studies confirmed the role of tightly bound Ca2+ in stabilizing the enzyme, but showed that the presence of a large excess of this ion results in reduced kinetic stability. The truncated forms of Xyn10A were less stable than the full-length enzyme, indicative of module/domain thermostabilizing interactions. Finally, possible roles of the two domains of unknown function are discussed in the light of this study. This is the first report on the thermostabilizing role of calcium on a modular family 10 xylanase that displays multiple calcium binding in three of its five domains/modules. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Extremophiles
volume
7
issue
6
pages
483 - 491
publisher
Springer
external identifiers
  • wos:000187157100006
  • pmid:12942350
  • scopus:4544366265
ISSN
1433-4909
DOI
language
English
LU publication?
yes
id
e3df26d8-9f5b-4c49-882a-dc9ea60bacd5 (old id 129012)
date added to LUP
2007-06-26 08:21:55
date last changed
2018-05-29 09:30:06
@article{e3df26d8-9f5b-4c49-882a-dc9ea60bacd5,
  abstract     = {The thermophilic bacterium Rhodothermus marinus produces a modular xylanase (Xyn10A) consisting of two N-terminal carbohydrate-binding modules (CBMs), followed by a domain of unknown function, and a catalytic module flanked by a fifth domain. Both Xyn10A CBMs bind calcium ions, and this study explores the effect of these ions on the stability of the full-length enzyme. Xyn10A and truncated forms thereof were produced and their thermostabilities were evaluated under different calcium loads. Studies performed using differential scanning calorimetry showed that the unfolding temperature of the Xyn10A was significantly dependent on the presence of Ca2+, and that the third domain of the enzyme binds at least one Ca2+. Thermal inactivation studies confirmed the role of tightly bound Ca2+ in stabilizing the enzyme, but showed that the presence of a large excess of this ion results in reduced kinetic stability. The truncated forms of Xyn10A were less stable than the full-length enzyme, indicative of module/domain thermostabilizing interactions. Finally, possible roles of the two domains of unknown function are discussed in the light of this study. This is the first report on the thermostabilizing role of calcium on a modular family 10 xylanase that displays multiple calcium binding in three of its five domains/modules.},
  author       = {Abou-Hachem, Maher and Olsson, Fredrik and Nordberg Karlsson, Eva},
  issn         = {1433-4909},
  language     = {eng},
  number       = {6},
  pages        = {483--491},
  publisher    = {Springer},
  series       = {Extremophiles},
  title        = {Probing stability of the modular thermostable xylanase Xyn10A,},
  url          = {http://dx.doi.org/},
  volume       = {7},
  year         = {2003},
}