利用琼脂糖(agarose)水凝胶将肌红蛋白(Mb)、血红蛋白(Hb)、辣根过氧化物酶(HRP)和过氧化氢酶(Cat)4种血红素蛋白质固定在裂解石墨电极表面,形成稳定的血红素蛋白质-agarose膜修饰电极。用紫外-可见和红外光谱及原子力显微法对血红素蛋白质-琼脂糖膜修饰电极进行了表征。紫外-可见和红外光谱显示,在琼脂糖凝胶中,血红素蛋白质保持原始构象。溶液的pH(3.0~10.0)可逆地改变血红素蛋白质的构象,从而影响其光谱性质。原子力显微图象表明血红素蛋白质与agarose水凝胶之间存在较强的作用。研究了血红素蛋白质催化还原O2、H2O2的机理。稳定的血红素蛋白质-agarose修饰电极能运用于H2O2的定量测定。
Four heme proteins, including myoglobin, hemoglobin, horseradish peoxidase and catalase, were immobilized on edge-plane pyrolytic graphite (EPG) electrodes by agarose. Ultraviolet visible (UV-Vis) and reflection absorption infrared (RAIR) spectra suggest that hemoproteins keep their original conformation in agarose film, and the conformation changes reversibly in a range of pH 3.0 ~ 10.0. AFM images indicate a stable and crystal-like structure is formed possibly due to the synergistic interaction of hydrogen bonding between agarose hydrogel and hemoproteins, suggesting a strong interaction between heme hemoglobin and agarose hydrogel. The mechanisms for catalytic reduction of oxygen and hydrogen peroxide by hemoproteins entrapped in agarose hydrogel were also explored.