caa a22 4500 397557876 CHVBK 20180308164808.0 cr unu---uuuuu 161202e199605 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021322 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021322 Kinetic Characterization of Antibody-Catalyzed Insertion of a Metal Ion into Porphyrin [Elektronische Daten] [Yasuko Kawamura-Konishi, Naoki Hosomi, Saburo Neya, T Sachiko Sugano, Noriaki Funasaki, Haruo Suzuki] The insertion of a copper(II) ion into mesoporphyrin by a monoclonal catalytic antibody has been investigated kinetically by measuring the increase in Soret absorbance due to the production of copper(II)-mesoporphyrin. The initial rate of the reaction showed saturation kinetics as a function of the mesoporphyrin concentration, while it increased linearly with an increase in the copper(II) concentration. Based on observations, a scheme for the reaction was proposed: mesoporphyrin binds to the antibody to form a complex, and copper(II) binds to the complex to yield copper(II)-mesoporphyrin. Kinetic parameters for the respective steps were estimated, and the thermodynamic parameters were calculated. The binding of mesoporphyrin to the antibody was endothermic and entropically driven. This implies that hydrophobic interactions are an important factor in the binding. Free energy profiles for the antibody-catalyzed and uncatalyzed reactions were drawn by use of the obtained thermodynamic parameter values. The results demonstrate that the rate acceleration by the antibody is ascribable to transition-state stabilization, and suggest that the structure of mesoporphyrin in the complex is more distorted than that of free mesoporphyrin. © by the Journal of Biochemistry Regular Papers nationallicence abzyme nationallicence catalytic antibody nationallicence kinetics nationallicence porphyrin nationallicence Kawamura-Konishi Yasuko Department of Biosciences, School of Science School of Nursing, Kitasat University Sagamihara, Kanagawa 228 aut Hosomi Naoki Department of Biosciences, School of Science School of Nursing, Kitasat University Sagamihara, Kanagawa 228 aut Neya Saburo Department of Physical Chemistry, Kyoto Pharmaceutical University Yamashina, Kyoto 607 aut Sugano T Sachiko Department of Biochemistry, School of Nursing, Kitasato University Sagamihara, Kanagawa 228 aut Funasaki Noriaki Department of Physical Chemistry, Kyoto Pharmaceutical University Yamashina, Kyoto 607 aut Suzuki Haruo Department of Biosciences, School of Science School of Nursing, Kitasat University Sagamihara, Kanagawa 228 aut The Journal of Biochemistry Oxford University Press 119/5(1996-05), 857-862 0021-924X 119:5<857 1996 119 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021322 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021322 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kawamura-Konishi Yasuko Department of Biosciences, School of Science School of Nursing, Kitasat University Sagamihara, Kanagawa 228 aut NATIONALLICENCE 700 1- Hosomi Naoki Department of Biosciences, School of Science School of Nursing, Kitasat University Sagamihara, Kanagawa 228 aut NATIONALLICENCE 700 1- Neya Saburo Department of Physical Chemistry, Kyoto Pharmaceutical University Yamashina, Kyoto 607 aut NATIONALLICENCE 700 1- Sugano T Sachiko Department of Biochemistry, School of Nursing, Kitasato University Sagamihara, Kanagawa 228 aut NATIONALLICENCE 700 1- Funasaki Noriaki Department of Physical Chemistry, Kyoto Pharmaceutical University Yamashina, Kyoto 607 aut NATIONALLICENCE 700 1- Suzuki Haruo Department of Biosciences, School of Science School of Nursing, Kitasat University Sagamihara, Kanagawa 228 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 119/5(1996-05), 857-862 0021-924X 119:5<857 1996 119 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford