Comparative physiological studies of regulation mechanism of hemoglobin function

通过比较各种动物血红蛋白的氧结合特性，我们打算深入了解每种血红蛋白独特或共同的分子机制，以及最后，成人血红蛋白的结构-功能关系。为了验证<alpha>89 His对成人血红蛋白的碱性玻尔效应有很大贡献的假设，我们测量了犬血红蛋白的玻尔效应，其中89位的His<alpha>被Tyr残基取代。结果不支持假设.在不同的实验条件下测定了四种两栖动物（爪蟾、大鲵、大鲵和隐鳃鲵）红细胞和血红蛋白的氧平衡曲线，并与人类血红蛋白的氧平衡曲线进行了比较。与人类血红蛋白相比，蝾螈血红蛋白显示出较低的氧亲和力和非常小的玻尔效应。此外，蝾螈血红蛋白几乎不受C1^1、Ca^&lt;2+&gt;、CO_2、ATP、IHP和无机磷酸盐的影响。虽然希尔系数随着pH的降低而变小，但由于快速自氧化，没有获得关于Root效应的结论性数据。

By comparing oxygen binding properties of hemoglobins of various animals, we intended to get insight into the molecular mechanisms that are unique for each hemoglobin or common to all of them, and finally, structure-function relationships in human adult hemoglobin.1. To examine the hypothesis that <alpha>89 His makes a great contribution to the alkaline Bohr effect of human adult hemoglobin, we measured the Bohr effect of canine hemoglobin in which His at <alpha>89 site is replaced by Tyr residue. The result did not support the hypothesis.2. Oxygen equilibrium curves for red cells and hemoglobins from four amphibian species: Onychodactylus japonicus, Megalobatrachus sligoi, Andrius japonicus, and Cryptobranchus alleganiensis were determined under a variety of experimental conditions and compared with each other or with those of human hemoglobin. The salamander hemoglobins showed lowered oxygen affinity and very small Bohr effect compared to those of human hemoglobin. Moreover, the salamander hemoglobins showed little heterotropic effects caused by C1^1, Ca^<2+>, CO_2, ATP, IHP and inorganic phosphate.3, To test a possible Root effect of hemoglobin from Xenopus laevis, its oxygen eauilibrium curves were measured at a wide pH range. Although the Hill coefficient became smaller as pH was decreased, no conclusive data on the Root effect was not obtained because of repid autoxidation.