著者

張 岩 今井 清博 小林 道頼

出版者

一般社団法人日本生物物理学会

雑誌

生物物理 (ISSN:05824052)

巻号頁・発行日

vol.47, no.3, pp.167-173, 2007-05-25

参考文献数

13

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The slope of the oxygen equilibrium curve (OEC) of mammalian-hemoglobin (Hb) is maximized at <i>S</i> (oxygen saturation) value of 0.38, and the slope of the <i>S</i> vs. <i>P</i>/<i>P</i>₅₀ (<i>P</i> is partial oxygen pressure; <i>P</i>₅₀ is <i>P</i> at <i>S</i> = 1/2) plot at a <i>P</i>/<i>P</i>₅₀ value of 1 is one-forth that of the Hill-coefficient (<i>n</i>). OECs of mammalian Hbs are designed to have an identical optimal <i>P</i>₅₀ value for O₂ delivery and the effectiveness of the Bohr shift (shift of OEC upon pH changes) at O₂ loading site. This fact is favorable for uptake and delivery of maximum amount of O₂ for fetal blood. To have the identical optimal <i>P</i>₅₀ value for O₂ delivery and for the efficiency of the Bohr shift, the relationship, <i>P</i>aO₂/<i>P</i>vO₂ = ((<i>n</i> + 1)/(<i>n</i> &minus; 1))^2/n, is required to hold, where <i>P</i>aO₂ and <i>P</i>vO₂ are <i>P</i> for arterial and venous bloods, respectively.<br>