【摘要】 研究了溶菌酶 ( Lysozyme,LE)在 KIO3存在下的极谱催化波 .在 0 .1 mol/ L HAc-Na Ac( p H4 .7±0 .1 )缓冲液中 ,LE有 1个由 Cys6～ Cys1 2 7间双硫键还原产生的可逆波 .其峰电位为 -0 .51 V( vs.Ag/Ag Cl) .当 KIO3存在时 ,在原电位处产生了 LE的极谱催化波 .该催化波是由于 KIO3及其中间价态衍生质点 (包括自由基 IO-· ,IO-·2 )氧化 LE还原产物巯基成双硫键所致 .这是蛋白质极谱催化波的一种新类型 .在 0 .1 mol/ L HAc-Na Ac( p H 4 .7± 0 .1 ) -1× 1 0 - 3mol/ L KIO3支持电解质中 ,LE催化波的灵敏度比其还原波的高两个数量级 ,峰电流与 LE浓度在 2× 1 0 - 7～ 1 .0× 1 0 - 6 mol/ L范围内有线性关系 .1 0 0倍半胱氨酸和胱氨酸不干扰 1 .0× 1 0 - 6 mol/ L LE的测定更多还原

【Abstract】 A polarographic catalytic wave of lysozyme(LE) in the presence of KIO 3 is described. In 01 mol/L HAc-NaAc(pH 47±01) buffer solution, LE yields a reversible wave with peak potential -051 V (vs. Ag/AgCl) due to the reduction of a disulfide bond between cys6—cys127. When KIO 3 is present in the acetate solution, LE produced a polarographic catalytic wave at original potential. The mechanism of the catalytic wave was considered that the disulfide bond was regenerated through oxidation reaction of reduction product —SH group by KIO 3 and its derived species with intermediate valence state(including free radical IO -· , IO -· 2). This is a new class of polarographic catalytic wave for protein. In 01 mol/L HAc-NaAc(pH 47±01)-1×10 -3 mol/L KIO 3 supporting electrolyte, the sensitivity of the catalytic wave is two orders of magnitude higher than that of the corresponding reduction wave. The peak current of the catalytic wave was linearly proportional to LE concentration in the range 2×10 -7 —1×10 -6 mol/L. 100-fold cystine and cystein do not interfere the determination of 1×10 -6 mol/L LE.更多还原