Maestre Rodrigo, Pazos Manuel, Medina Isabel
Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, E-36208 Vigo, Spain.
J Agric Food Chem. 2009 Aug 12;57(15):7013-21. doi: 10.1021/jf9006664.
The capacity of Atlantic pollock ( Pollachius pollachius ), seabass ( Dicentrarchus labrax ), and horse mackerel ( Trachurus trachurus ) hemoglobin (Hb) to promote lipid oxidation has been evaluated in liposomes and washed minced horse mackerel muscle. The pro-oxidant ability of fish Hbs was related with their vulnerability to suffer oxidation to metHb and release hemin either in spontaneous situation or in the presence of two representative lipid oxidation products, linolein hydroperoxides and trans-2-pentenal. The results indicated similar effectiveness to promote lipid oxidation in liposomes and washed fish muscle: pollock Hb > horse mackerel Hb > seabass Hb. Pollock Hb showed a more elevated autoxidation rate and spontaneous hemin loss and also faster oxidation to metHb in the presence of hydroperoxides and trans-2-pentenal. The autoxidation and spontaneous hemin loss rates were intermediate for horse mackerel Hb, whereas seabass Hb exhibited the highest stability. The isoelectrofocusing (IEF) pattern of pollock Hb revealed the presence of isoforms with elevated anionic character, which are known to have poor oxygen affinity at the pH values found in fish muscle (pH 7.0-5.5). In agreement with the IEF patterns, pollock Hb was less oxygenated at pH 6.8, and seabass Hb exhibited more oxygenation than did horse mackerel. MetHb forms were significantly more effective in catalyzing lipid oxidation than the corresponding reduced fish Hbs and free hemin. The present investigation highlights a direct correlation between the pro-oxidant capacity of fish Hbs and their susceptibility to undergo metHb formation and hemin loss and also suggests a potential role of lipid oxidation byproducts in activating the pro-oxidative action of hemoglobin.
已在脂质体和清洗过的切碎竹荚鱼肌肉中评估了大西洋鳕鱼（Pollachius pollachius）、海鲈（Dicentrarchus labrax）和竹荚鱼（Trachurus trachurus）血红蛋白（Hb）促进脂质氧化的能力。鱼类血红蛋白的促氧化能力与其在自发情况下或存在两种代表性脂质氧化产物亚油酸氢过氧化物和反式-2-戊烯醛时氧化为高铁血红蛋白（metHb）并释放血红素的易感性有关。结果表明，在脂质体和清洗过的鱼肉中促进脂质氧化的效果相似：鳕鱼血红蛋白 > 竹荚鱼血红蛋白 > 海鲈血红蛋白。鳕鱼血红蛋白显示出自氧化速率更高、自发血红素损失更快，并且在存在氢过氧化物和反式-2-戊烯醛时氧化为高铁血红蛋白的速度也更快。竹荚鱼血红蛋白的自氧化和自发血红素损失速率处于中间水平，而海鲈血红蛋白表现出最高的稳定性。鳕鱼血红蛋白的等电聚焦（IEF）图谱显示存在具有较高阴离子特性的同工型，已知这些同工型在鱼肌肉中发现的pH值（pH 7.0 - 5.5）下具有较差的氧亲和力。与IEF图谱一致，鳕鱼血红蛋白在pH 6.8时的氧合程度较低，而海鲈血红蛋白的氧合程度比竹荚鱼更高。高铁血红蛋白形式在催化脂质氧化方面比相应的还原型鱼类血红蛋白和游离血红素更有效。本研究突出了鱼类血红蛋白的促氧化能力与其形成高铁血红蛋白和血红素损失的易感性之间的直接相关性，并且还表明脂质氧化副产物在激活血红蛋白的促氧化作用中可能发挥的作用。
