TY - JOUR
T1 - Unusual cyanide bindings to a heme-regulated phosphodiesterase from Escherichia coli
T2 - Effect of Met95 mutations
AU - Watanabe, Miki
AU - Matsui, Toshitaka
AU - Sasakura, Yukie
AU - Sagami, Ikuko
AU - Shimizu, Toru
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002
Y1 - 2002
N2 - In order to understand heme environment of a heme-regulated phosphodiesterase (Ec DOS), the binding behavior of cyanide to the Fe (III) complex was examined. Interestingly, the rate of cyanide binding to full-length Ec DOS was unusually slow with kon = 0.0022mM-1 s-1, while the rate for the isolated heme domain of Ec DOS (0.045mM-1 s-1) was 20-fold higher. Ala and Leu mutations at Met95, which has been suggested to be a heme axial ligand, increased the kon rate 11- and 8-fold, respectively, and dramatically decreased the cyanide dissociation rate from the isolated heme domain. His mutation at Met95, on the other hand, caused a 17-fold decrease in the kon value. We discuss the unusual cyanide binding behavior and the role of Met95 in controlling cyanide binding.
AB - In order to understand heme environment of a heme-regulated phosphodiesterase (Ec DOS), the binding behavior of cyanide to the Fe (III) complex was examined. Interestingly, the rate of cyanide binding to full-length Ec DOS was unusually slow with kon = 0.0022mM-1 s-1, while the rate for the isolated heme domain of Ec DOS (0.045mM-1 s-1) was 20-fold higher. Ala and Leu mutations at Met95, which has been suggested to be a heme axial ligand, increased the kon rate 11- and 8-fold, respectively, and dramatically decreased the cyanide dissociation rate from the isolated heme domain. His mutation at Met95, on the other hand, caused a 17-fold decrease in the kon value. We discuss the unusual cyanide binding behavior and the role of Met95 in controlling cyanide binding.
KW - Axial ligand
KW - Cyanide
KW - Heme sensor
KW - Optical absorption
KW - Phosphodiesterase
KW - Site-directed mutagenesis
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U2 - 10.1016/S0006-291X(02)02621-9
DO - 10.1016/S0006-291X(02)02621-9
M3 - Article
C2 - 12437964
AN - SCOPUS:0036436657
VL - 299
SP - 169
EP - 172
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 2
ER -