TY - JOUR
T1 - Introduction of a specific binding domain on myoglobin surface by new chemical modification
AU - Hayashi, Takashi
AU - Ando, Tsutomu
AU - Matsuda, Takaaki
AU - Yonemura, Hiroaki
AU - Yamada, Sunao
AU - Hisaeda, Yoshio
N1 - Funding Information:
We thank Dr. M. Waki (Kyushu University) for his helpful discussion about synthetic route of 1 . This work was supported by The Fujisawa Foundation and a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, Japan.
PY - 2000
Y1 - 2000
N2 - A new myoglobin, reconstituted with a modified zinc protoporphyrin, having a total of four ammonium groups at the terminal of the two propionate side chains was constructed to introduce a substrate binding site. The protein with a positively charged patch on the surface formed a stable complex with negatively charged substrates, such as hexacyanoferrate(III) and anthraquinonesulfonate via an electrostatic interaction. The complexation was monitored by fluorescence quenching due to singlet electron transfer from the photoexcited reconstituted zinc myoglobin to the substrates. The binding properties were evaluated by Stern-Volmer plots from the fluorescence quenching of the zinc myoglobin by a quencher. Particularly, anthraquinone-2,7-disulfonic acid showed a high affinity with a binding constant of 1.5x105 M-1 in 10 mM phosphate buffer, pH 7.0. In contrast, the plots upon the addition of anthraquinone-2-sulfonic acid at different ionic strengths indicated that the complex was formed not only by an electrostatic interaction but also by a hydrophobic contact. The findings from the fluorescence studies conclude that the present system is a useful model for discussion of electron transfer via non-covalently linked donor-acceptor pairing on the protein surface. Copyright (C) 2000 Elsevier Science B.V.
AB - A new myoglobin, reconstituted with a modified zinc protoporphyrin, having a total of four ammonium groups at the terminal of the two propionate side chains was constructed to introduce a substrate binding site. The protein with a positively charged patch on the surface formed a stable complex with negatively charged substrates, such as hexacyanoferrate(III) and anthraquinonesulfonate via an electrostatic interaction. The complexation was monitored by fluorescence quenching due to singlet electron transfer from the photoexcited reconstituted zinc myoglobin to the substrates. The binding properties were evaluated by Stern-Volmer plots from the fluorescence quenching of the zinc myoglobin by a quencher. Particularly, anthraquinone-2,7-disulfonic acid showed a high affinity with a binding constant of 1.5x105 M-1 in 10 mM phosphate buffer, pH 7.0. In contrast, the plots upon the addition of anthraquinone-2-sulfonic acid at different ionic strengths indicated that the complex was formed not only by an electrostatic interaction but also by a hydrophobic contact. The findings from the fluorescence studies conclude that the present system is a useful model for discussion of electron transfer via non-covalently linked donor-acceptor pairing on the protein surface. Copyright (C) 2000 Elsevier Science B.V.
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U2 - 10.1016/S0162-0134(00)00153-7
DO - 10.1016/S0162-0134(00)00153-7
M3 - Article
C2 - 11132620
AN - SCOPUS:0033734199
VL - 82
SP - 133
EP - 139
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
SN - 0162-0134
IS - 1-4
ER -