化学通报(网络版)
化學通報(網絡版)
화학통보(망락판)
Chemistry Online
1999年
1期
,共1页
涂楚桥%梁宏**%王光辉
塗楚橋%樑宏**%王光輝
도초교%량굉**%왕광휘
漆树漆酶%Pt(Ⅳ)%抑制和活化
漆樹漆酶%Pt(Ⅳ)%抑製和活化
칠수칠매%Pt(Ⅳ)%억제화활화
Rhus vernicifera laccase%Pt(Ⅳ)%inhibition and activation
通过动力学方法研究了pH 4.4和30±0.2℃条件下Pt(Ⅳ)对漆树漆酶催化氧化5,6-二溴-2,3-二氰基氢醌(DDBQH2)的影响.结果表明,当Pt(Ⅳ)浓度较低时,它对酶催反应有混合性抑制作用,竞争性和非竞争性抑制剂常数分别为3.0×10-6和7.5×10-6 mol/L;随着Pt(Ⅳ)浓度的增加,抑制作用逐渐转变为活化作用,这种活化作用暂时被称为混合性活化作用,竞争性和非竞争性活化剂常数分别为285.7×10-6和62.5×10-6 mol/L.随着Pt(Ⅳ)与漆酶混合时间的延长,Pt(Ⅳ)对漆酶活性的活化作用明显加强,但抑制作用变化不大.与Pt(Ⅳ)混合一定时间后的漆酶的吸收光谱表明,漆酶分子中的Ⅰ型铜位和Ⅲ型铜位可能是Pt(Ⅳ)的作用位点.
通過動力學方法研究瞭pH 4.4和30±0.2℃條件下Pt(Ⅳ)對漆樹漆酶催化氧化5,6-二溴-2,3-二氰基氫醌(DDBQH2)的影響.結果錶明,噹Pt(Ⅳ)濃度較低時,它對酶催反應有混閤性抑製作用,競爭性和非競爭性抑製劑常數分彆為3.0×10-6和7.5×10-6 mol/L;隨著Pt(Ⅳ)濃度的增加,抑製作用逐漸轉變為活化作用,這種活化作用暫時被稱為混閤性活化作用,競爭性和非競爭性活化劑常數分彆為285.7×10-6和62.5×10-6 mol/L.隨著Pt(Ⅳ)與漆酶混閤時間的延長,Pt(Ⅳ)對漆酶活性的活化作用明顯加彊,但抑製作用變化不大.與Pt(Ⅳ)混閤一定時間後的漆酶的吸收光譜錶明,漆酶分子中的Ⅰ型銅位和Ⅲ型銅位可能是Pt(Ⅳ)的作用位點.
통과동역학방법연구료pH 4.4화30±0.2℃조건하Pt(Ⅳ)대칠수칠매최화양화5,6-이추-2,3-이청기경곤(DDBQH2)적영향.결과표명,당Pt(Ⅳ)농도교저시,타대매최반응유혼합성억제작용,경쟁성화비경쟁성억제제상수분별위3.0×10-6화7.5×10-6 mol/L;수착Pt(Ⅳ)농도적증가,억제작용축점전변위활화작용,저충활화작용잠시피칭위혼합성활화작용,경쟁성화비경쟁성활화제상수분별위285.7×10-6화62.5×10-6 mol/L.수착Pt(Ⅳ)여칠매혼합시간적연장,Pt(Ⅳ)대칠매활성적활화작용명현가강,단억제작용변화불대.여Pt(Ⅳ)혼합일정시간후적칠매적흡수광보표명,칠매분자중적Ⅰ형동위화Ⅲ형동위가능시Pt(Ⅳ)적작용위점.
Kinetic experiments were performed to study the effects of Pt(Ⅳ) on the oxidation of 5,6-dibromo-2,3-dicyanohydroquinone(DDBQH2) catalyzed by Rhus vernicifera laccase under condition of pH 4.4 and 30±0.2℃. The results showed that the mixed inhibition could be observed when Pt(Ⅳ) was at low concentrations, the competitive and non-competitive inhibition constants were 3.0×10-6 and 7.5×10-6 mol/L, respectively. With the increase of Pt(Ⅳ) concentration, the inhibition was gradually converted into activation which we suggest to be mixed type, and the competitive and non-competitive activation constants were 285.7×10-6 and 62.5×10-6 mol/L, respectively. With the extension of mixed time of Pt(Ⅳ) with laccase, the activation on the laccase activity was obvious strengthened, but the inhibition only went up a little. The absorption spectrum of laccase mixed with Pt(Ⅳ) suggests that it is the type 1 site and type 3 site in laccase with which Pt(Ⅳ) interacts.