TY - JOUR
T1 - Enhanced laccase stability through mediator partitioning into hydrophobic ionic liquids
AU - Rehmann, Lars
AU - Ivanova, Ekaterina
AU - Gunaratne, H. Q. Nimal
AU - Seddon, K.R.
AU - Stephens, Gill
PY - 2014/3/1
Y1 - 2014/3/1
N2 - Laccase-mediator systems have numerous potential uses for green oxidations, but their practical use may be limited because the reactive, oxidised mediators deactivate the enzyme. TEMPO, 4-hydroxybenzyl alcohol, phenothiazine and 2-hydroxybiphenyl caused almost complete deactivation of laccase from Trametes versicolor within 24-140 h. By contrast, 18% activity was retained after 188 h in controls without mediator, and 15% in the presence of ABTS. A biphasic reaction system was developed to protect the laccase, by partitioning the mediator into water-immiscible ionic liquids. In the presence of [C mim][AOT], laccase retained 54, 35, 35 and 41% activity after 188 h in the presence of 4-hydroxybenzyl alcohol, phenothiazine and 2-hydroxybiphenyl and ABTS, respectively, whilst 30% activity was retained in the presence of [N][Sac] and TEMPO. The protection against deactivation by the mediators correlated strongly with the distribution coefficients of the mediators between ionic liquids and water.
AB - Laccase-mediator systems have numerous potential uses for green oxidations, but their practical use may be limited because the reactive, oxidised mediators deactivate the enzyme. TEMPO, 4-hydroxybenzyl alcohol, phenothiazine and 2-hydroxybiphenyl caused almost complete deactivation of laccase from Trametes versicolor within 24-140 h. By contrast, 18% activity was retained after 188 h in controls without mediator, and 15% in the presence of ABTS. A biphasic reaction system was developed to protect the laccase, by partitioning the mediator into water-immiscible ionic liquids. In the presence of [C mim][AOT], laccase retained 54, 35, 35 and 41% activity after 188 h in the presence of 4-hydroxybenzyl alcohol, phenothiazine and 2-hydroxybiphenyl and ABTS, respectively, whilst 30% activity was retained in the presence of [N][Sac] and TEMPO. The protection against deactivation by the mediators correlated strongly with the distribution coefficients of the mediators between ionic liquids and water.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84894626244&partnerID=8YFLogxK
U2 - 10.1039/c3gc42189a
DO - 10.1039/c3gc42189a
M3 - Article
AN - SCOPUS:84894626244
SN - 1463-9262
VL - 16
SP - 1462
EP - 1469
JO - Green Chemistry
JF - Green Chemistry
IS - 3
ER -