不同离子对漆酶酶活的影响

Effect of Different Ions on Laccase Enzyme Activity

设置一系列不同种类、不同浓度的离子溶液,探究其对漆酶酶活的影响。结果表明,阳离子中Fe2+、Fe3+对漆酶的抑制作用显著,并分析了离子浓度对漆酶的影响以及不同离子对漆酶的抑制机理。分析表明Fe2+可能是通过与2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基结合影响漆酶酶活,Fe3+可能是通过影响或置换漆酶中的部分铜离子影响漆酶活性,其中因为漆酶的活性中心是由四个铜离子组成,特别分析了Cu2+对漆酶活性的影响,Cu2+可能是通过与漆酶中的酸性氨基酸残基作用或通过影响漆酶的电荷平衡影响漆酶活性。在常见的阴离子溶液中,CO32-抑制漆酶酶活,NO3-和SO42-对漆酶有一定程度的激活,Cl-轻微抑制漆酶酶活。分析表明阴离子的抑制作用可能是通过与底物分子竞争Ⅱ铜中的某一个位点来实现,激活作用可能是通过修饰漆酶氨基酸残基来实现。还研究了不同类型离子的复配,结果显示不同类型的复配对漆酶的影响方式也不同,但主要是通过作用于漆酶活性位点来影响酶活。

Set up a series of different types and different concentrations of ionic solutions to explore their effects on laccase enzyme activity.The inhibitory effect of Fe2+,Fe3+on laccase was significant,and the effect of ion concentration on laccase was analyzed,and the inhibition mechanism of these ions was analyzed.The analysis indicated that Fe2+may affect the laccase activity by binding to ABTS free radicals,Fe3+may affect the laccase activity by affecting or replacing a portion of the copper ions of laccase.Because the active center of laccase is composed of four copper ions,the effect of Cu2+on laccase activity is particularly analyzed,Cu2+may affect laccase activity by acting with acidic amino acid residues in the laccase or by affecting the charge balance of the laccase.In common anion solutions,CO2-3 inhibits laccase activity,NO-3 and SO2-4 have a certain degree of activation of laccase,and Cl-slightly inhibits laccase activity;analysis indicates that anion inhibition may through substrate the molecule competes for a site inⅡcopper,and the activation may be achieved by modifying the laccase amino acid residues.The compounding of different types of ions was also investigated.The results showed that different types of complex affected laccases in different ways,but mainly affected the enzyme activity by acting on the laccase active site.