In:
Biotechnology Progress, Wiley, Vol. 18, No. 2 ( 2002-01), p. 276-281
Kurzfassung:
We wish to report the attainment of the highest ever T opt by introducing approximately two aromatic rings through chemical modification of surface carboxyl groups in carboxymethylcellulase from Scopulariopsis sp. with concomitant decrease in V max , K m , and optimum pH! This extraordinary enhancement in thermophilicity of aniline‐coupled CMCase ( T opt = 122 °C) by a margin of 73 °C as compared with the native enzyme ( T opt = 49 °C) is the highest reported for any mesophilic enzyme that has been modified either through chemical modification or site‐directed mutagenesis. It is also reported for the first time that aniline coupled CMCase (ACC) is simultaneously thermostable in aqueous as well as water‐miscible organic solvents. The T opt of native CMCase and ACC were 25 and 90 °C, respectively, in 40% (v/v) aqueous dioxan. The modified enzyme was also stabilized against irreversible thermal denaturation. Therefore, at 55 °C, ACC had a half‐life of 136 min as compared with native CMCase whose half‐life was only 5 min. We believe that the reasons for this elevated thermostability and thermophilicity are surface aromatic–aromatic interactions and aromatic interactions with the sugar backbone of the substrate, respectively.
Materialart:
Online-Ressource
ISSN:
8756-7938
,
1520-6033
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
2002
ZDB Id:
2003526-3
SSG:
12
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