汞对人类胎盘碱性磷酸酶活力与荧光光谱的影响  

THE EFFECT OF MERCURY ON CATALYTIC ACTIVITY AND FLUORESCENCE SPECTRA OF HUMAN PLACENTAL ALKALINE PHOSPHATASE

作　　者：耿芳宋[1] 刘洪明 王秀丽[1] 杜卫[1] 张社华[1] 

机构地区：[1]青岛医学院

出　　处：《青岛医学院学报》1999年第1期16-18,共3页Acta Academiae Medicinae Qingdao Universitatis

基　　金：山东省卫生厅科研基金

摘　　要：目的研究汞对人类胎盘碱性磷酸酶（ＰＬＡＰ）活力及其荧光光谱的影响，以探讨汞对ＰＬＡＰ抑制的分子机制。②方法应用分光光度法测定不同浓度ＨｇＣｌ２存在下的酶活力，用荧光法检测其荧光光谱；用双倒数作图法确定ＨｇＣｌ２对该酶的抑制类型。③结果当ＨｇＣｌ２浓度为０．２５ｍｍｏｌ／Ｌ时，酶活力及其荧光强度迅速下降，最大发射峰位由３４７ｎｍ蓝移至３４０ｎｍ；ＨｇＣｌ２浓度为０．２５～１．００ｍｍｏｌ／Ｌ时，酶活力、荧光强度及峰位均无显著变化；当ＨｇＣｌ２浓度＞１．００ｍｍｏｌ／Ｌ时，随其浓度增加，酶活力和荧光强度又快速下降，但峰位不变；ＨｇＣｌ２浓度高达１０．００ｍｍｏｌ／Ｌ时，酶仍有部分活力。ＨｇＣｌ２是ＰＬＡＰ混合性抑制剂，其抑制常数为３．６０ｍｍｏｌ／Ｌ．④结论ＨｇＣｌ２抑制了ＰＬＡＰ的活力，并使其构象发生了改变。Objective \ To study the effect of mercury on catalytic activity and fluorescence spectra of human placental alkaline phosphatase(PLAP) and discuss the molecular mechanism of mercury in inhibiting PLAP.\ X]Methods \ Spectrophotometry was used to study the activity of PLAP under different concentrations of HgCl2. Fluorometry was used to observe the fluorescence spectra. The inhibition type of HgCl2 on PLAP was determined by using the double reciprocal plot.\ Results \ When the concentration of HgCl2 was 0.25mmol/L, PLSP activity and emission intensity were greatly decreased and the emission maximum was blueshifted from 347nm to 340nm. When the concentration of HgCl2 was between 0.25-1.00mmol/L, no obvious changes of PLAP activity, emission intensity and emission maximum were observed. When the concentration of HgCl2 was higher than 1.00mmol/L, the PLAP activity and emission intensity were greatly decreased again along with the decrement of HgCl2 concentration, while the emission maximum kept unchanged, At the concentration of 10mmol/L, some PLAP activity could still be observed. HgCl2 was a mixedcompetitive inhibitor of PLAP and its inhibition constant(ki) was 3.60mmol/L.\ Conclusion \ The PLAP activity was inhibited and its conformation was changed by HgCl2.

关 键 词：汞 碱性磷酸酶 荧光光谱 胎盘 PLAP 

分 类 号：R714.56[医药卫生—妇产科学] Q55[医药卫生—临床医学]