Nedjar-Arroume N, Castellano A, Piot J M, Guillochon D
Laboratoire de Technologie des Substances Naturelles, IUT 'A' Lille I, Villeneuve D'Ascq, France.
Biotechnol Appl Biochem. 1993 Aug;18(1):25-35.
The stabilization of haemoglobin (Hb) in water/alcohol solvents (ethanol, butan-1-ol, ethylene glycol and glycerol) against autoxidation, a major barrier to the successful use of Hb in biological and medical engineering was studied, with these solvents, a large decrease in the autoxidation rate is observed over a range of concentrations. Studies on the effect of Hb concentration on autoxidation showed that, irrespective of the Hb concentration, oxyHb is more stabilized in water/alcohol solvents than in water. In these solvents, at the concentration exhibiting the maximal stabilizing effect, the oxygen affinity of Hb was little disturbed, but the changes in enthalpy and entropy of activation increased with the stabilization effect of alcohol. The impact of alcohols on the thermal denaturation of metHb was studied. We observed that metHb is less stable in ethanol and butan-1-ol than in water, whereas the opposite is observed with glycerol and ethylene glycol. The strong stability of oxyHb observed with these solvents could result both from an increase in water structure and an increase of viscosity. Finally, e.p.r. has shown that alcohols lead to an increase of the global distance between the nitrogens of proximal histidine (F8) and nitric oxide in the nitrosyl Hb.
研究了血红蛋白（Hb）在水/醇类溶剂（乙醇、正丁醇、乙二醇和甘油）中抗自氧化的稳定性，自氧化是Hb在生物和医学工程中成功应用的主要障碍。在这些溶剂中，在一定浓度范围内观察到自氧化速率大幅下降。关于Hb浓度对自氧化影响的研究表明，无论Hb浓度如何，氧合血红蛋白（oxyHb）在水/醇类溶剂中比在水中更稳定。在这些溶剂中，在表现出最大稳定作用的浓度下，Hb的氧亲和力几乎不受干扰，但活化焓和熵的变化随着醇的稳定作用而增加。研究了醇类对高铁血红蛋白（metHb）热变性的影响。我们观察到，高铁血红蛋白在乙醇和正丁醇中比在水中更不稳定，而在甘油和乙二醇中则观察到相反的情况。在这些溶剂中观察到的氧合血红蛋白的强稳定性可能是由于水结构的增加和粘度的增加。最后，电子顺磁共振（e.p.r.）表明，醇类会导致亚硝基血红蛋白中近端组氨酸（F8）的氮原子与一氧化氮之间的整体距离增加。
