Nigen A M, Manning J M, Alben J O
J Biol Chem. 1980 Jun 25;255(12):5525-9.
A hemoglobin hybrid (alpha 2c beta 2 Prov) in which the alpha chains have NH2-terminal residues that have been blocked specifically by carbamylation and beta chains that have been derived from hemoglobin Providence I (beta 82 Lys leads to Asn) was prepared. This derivative shows a small but significant dependence of its oxygen equilibrium curve on the concentration of chloride, phosphate, or nitrate. These data were compared with oxygen-linked anion binding to hemoglobins A and Providence, and to the carbamylated hybrid, alpha 2c beta 2, by fitting equations to the data with the use of MULTIFIT II, a nonlinear curve-fitting program. Dependence of the anion dissociation constants from deoxygenated (KD) and fully oxygenated (Ko) hemoglobins upon the mathematical model is described. The data provide further support that Val-1 (alpha) and Lys-82 (beta) of hemoglobin are major, oxygen-linked binding sites for small inorganic anions and suggested that a third oxygen-linked site may also be present.
制备了一种血红蛋白杂种（α2cβ2Prov），其中α链的NH2末端残基已通过氨甲酰化特异性封闭，β链来源于血红蛋白普罗维登斯I（β82赖氨酸突变为天冬酰胺）。该衍生物的氧平衡曲线对氯离子、磷酸根离子或硝酸根离子浓度表现出微小但显著的依赖性。通过使用非线性曲线拟合程序MULTIFIT II将方程拟合到数据上，将这些数据与血红蛋白A、普罗维登斯以及氨甲酰化杂种α2cβ2的氧结合阴离子进行了比较。描述了阴离子从脱氧血红蛋白（KD）和完全氧合血红蛋白（Ko）的解离常数对数学模型的依赖性。这些数据进一步支持了血红蛋白的Val-1（α）和Lys-82（β）是小无机阴离子的主要氧结合位点，并表明可能还存在第三个氧结合位点。
