Yamada Y, Fukuda W, Hirooka K, Hiromoto T, Nakayama JI, Imanaka T, Fukusaki EI, Fujiwara S. Efficient in vitro synthesis of cis-polyisoprenes using a thermostable cis-prenyltransferase from a hyperthermophilic archaeon Thermococcus kodakaraensis.
J Biotechnol 2009;
143:151-6. [PMID:
19583987 DOI:
10.1016/j.jbiotec.2009.06.026]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 05/26/2009] [Accepted: 06/21/2009] [Indexed: 10/20/2022]
Abstract
The Tk-idsB encoding cis-prenyltransferase which catalyzes consecutive cis-condensation of isopentenyl diphosphate to allylic diphosphate was isolated from a hyperthermophilic archaeon Thermococcus kodakaraensis, and enzymatic characteristics of the recombinant Tk-IdsB were examined. Tk-IdsB was not fully denatured even at 90 degrees C and preferably utilizes both C(10) and C(15) allylic diphosphates to yield mainly the C(60)-C(65) products. Based on structural models, single alanine-substitution mutants at Glu68, Lys109, or Leu113 were constructed, showing that all the three produced longer chains (C(65)-C(70)) than the wild-type and the substitution at 109 (K109A) was the most effective. Tk-IdsB was applied to an organic-aqueous dual-phase system and more than 90% of the products were recovered from the organic phase when 1-butanol or 1-pentanol was overlaid. When 1-octanol was overlaid, 70% of the products were obtained from the upper organic phase. The product distributions were changed depending on the hydrophobicity of organic solvents used. Tk-IdsB was then immobilized onto silica beads to make Tk-IdsB more tolerant, showing that half-life of enzyme at 80 degrees C was prolonged by immobilization. When the immobilized Tk-IdsB was applied in the organic-aqueous dual-phase system, immobilized Tk-IdsB catalyzed consecutive condensation more efficiently than the unimmobilized one.
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