水合溶菌酶及其热稳定性的NMR研究

STUDIES ON HYDRATED LYSOZYME AND ITS THERMAL STABILITY BY NMR

本文用90MHz脉冲NMB波谱仪记录了具不同含水量的溶菌酶的质子宽谱线NMR谱图及自由感应衰减曲线,并记录了水合度为0.10及0.19克水/克溶菌酶的溶菌酶样品从室温到热变性温度范围内的谱图.用线宽参量随水合度及温度的变化讨论溶菌酶在水合及热变性过程中溶菌酶分子及水分子运动性的变化.结果表明,溶菌酶分子及水分子的运动性与水合溶菌酶中的水含量密切相关;低水含量的水合溶菌酶在热变性过程中酶分子运动性的变化经历了两个转变,分别对应于酶分子间的解缔合及分子内的解旋.

The proton wide-line NMR spectra and free induction decay curves of hydr- ated lysozyme containing different water content and proton wide-line NMR spectra of hydrated lysozyme(0.10 and 0.19 gH2O/g Lys. respectively)in the temperature range from room temp. to denaturation temp. have been recorded by 90 MHz pulse NMR spectrometer SXP 4-100. The variation of the molecular motions of lysozyme and water in the process of hydration and tnermodcnaturation has been discussed by the changes of line-width parameter with hydration and temperature. The results show that the molecular motions of lysozyme and absorbed water depend on water content and there are two transitions of the molecular motion of lysozyme containing lower water content in the process of thermodenaturation. The two transitions have been considered intermoleculor dissociation and intramolecular unfolding in lysozyme respectively.