Oxidative biodegradation of 4-chlorophenol by using recombinant monooxygenase cloned and overexpressed from Arthrobacter chlorophenolicus A6.
In this study, cphC-I and cphB, encoding a putative two-component flavin-diffusible monooxygenase (TC-FDM) complex, were cloned from Arthrobacter chlorophenolicus A6. The corresponding enzymes were overexpressed to assess the feasibility of their utilization for the oxidative decomposition of 4-chlorophenol (4-CP). Soluble CphC-I was produced at a high level (∼50%), and subsequently purified. Since CphB was expressed in an insoluble form, a flavin reductase, Fre, cloned from Escherichia coli was used as an alternative reductase. CphC-I utilized cofactor FADH2, which was reduced by Fre for the hydroxylation of 4-CP. This recombinant enzyme complex exhibited a higher specific activity for the oxidation of 4-CP (45.34U/mg-protein) than that exhibited by CphC-I contained in cells (0.18U/mg-protein). The Michaelis-Menten kinetic parameters were determined as: vmax=223.3μM·min-1, KM=249.4μM, and kcat/KM=0.052min-1·μM-1. These results could be useful for the development of a new biochemical remediation technique based on enzymatic agents catalyzing the degradation of phenolic contaminants.
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Christina
C
Kang
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Jun Won
JW
Yang
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Wooyoun
W
Cho
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Seonyeong
S
Kwak
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Sungyoon
S
Park
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
Yejee
Y
Lim
Civil Engineering, Gwangju University, 277 Hyodeok-ro, Nam-gu, Gwanju 61743, Republic of Korea.
Jae Wan
JW
Choe
Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea. Electronic address: hankim@konkuk.ac.kr.
Han S
HS
Kim
D001173:Arthrobacter; D001673:Biodegradation, Environmental; D002733:Chlorophenols / Q000378:metabolism*; D004926:Escherichia coli; D006899:Mixed Function Oxygenases
D002733:Chlorophenols; C029107:4-chlorophenol; D006899:Mixed Function Oxygenases
4-Chlorophenol; Arthrobacter chlorophenolicus A6; Enzymatic decomposition; Flavin reductase; Two-component flavin-diffusible monooxygenase