系统性红斑狼疮患者和正常人血清IgG结构的光谱学研究

A STUDY ON THE CONFORMATION OF IgGs FROM THE SERA OF SLE PATIENTS AND NORMAL PERSONS BY SPECTROSCOPIES

园二色谱和萤光光谱的研究表明，ＳＬＥ患者和正常人血清ＩｇＧ分子以及ＩｇＧ－Ｆ（ａｂ＇）２片段在结构上都存在明显的差异．同正常人相比，ＳＬＥ患者血清ＩｇＧ园二色谱中２１３ｎｍ处负峰的椭园值比正常人的高出近一倍，ＩｇＧ分子中的疏水基团（如Ｔｒｐ等）处于正电区，并且趋向于分布在蛋白质分子的表面．ＤＮＡ时ＩｇＧ空间结构影响很小，虽然高浓度的ＤＮＡ有熄灭ＩｇＧ分子萤光的作用，但是低浓度ＤＮＡ对正常人血清ＩｇＧ的萤光几乎没有影响．Ｆｅ２＋引起ＳＬＥ患者和正常人ＩｇＧ的紫外吸收光谱出现明显的差别。

The conformation of IgGs from the sera of systemic lupus erythematosus(SLE)patients and normal persons were studied in this paper.The results showed that the conformation differences between the two kinds of IgG molecules were obvious. The θ value of the peak at 213nm in SLE IgG CD spectrum was as twice as that of normal IgG. In comparison with normal IgG, the hydrophobic groups(eg.Trp)of SLE IgG molecules resided at the positive electricity regions and were exposed more to the surface of lgG molecules.Although DNA of high concentration might give rise to the quenching of IgG fluoresence, DNA of low concentration had but little effat on the nounal IgG fluormence. Trace of Fe2+ would makemuch difference in the UV spectra of SLE and nounal IgG.