Jose S A, Griffiths H, Lunec J, Mageed R A, Jefferis R
Department of Immunology, Medical School, University of Birmingham, U.K.
Mol Immunol. 1987 Nov;24(11):1145-50. doi: 10.1016/0161-5890(87)90160-x.
It has previously been demonstrated that exposure of polyclonal IgG to free radicals results in denaturation evidenced by aggregation, auto-fluorescence and destruction of cysteine, proline and aromatic amino acids. In the present study we have used a panel of monoclonal antibodies (McAb) to epitopes expressed on the IgG3 heavy chain to detect changes in antigenicity. When IgG3 was exposed to u.v. irradiation, as a source of free radicals, subclass specific epitopes were rapidly lost whilst other epitopes were unaffected. Prolonged exposure resulted in further denaturation and a progressive loss of expression of further epitopes. The IgG3 subclass specific McAb are specific to epitopes localized to the hinge region of IgG3. Thus, this exposed cysteine and proline rich region is shown to be particularly vulnerable to free radical attack; however, prolonged exposure results in structural alterations throughout the heavy chain.
先前已经证明，多克隆IgG暴露于自由基会导致变性，表现为聚集、自发荧光以及半胱氨酸、脯氨酸和芳香族氨基酸的破坏。在本研究中，我们使用了一组针对IgG3重链上表达的表位的单克隆抗体（McAb）来检测抗原性的变化。当IgG3暴露于作为自由基来源的紫外线照射时，亚类特异性表位迅速丧失，而其他表位未受影响。长时间暴露导致进一步变性以及更多表位表达的逐渐丧失。IgG3亚类特异性McAb对定位于IgG3铰链区的表位具有特异性。因此，这个富含半胱氨酸和脯氨酸的暴露区域显示出特别容易受到自由基攻击；然而，长时间暴露会导致整个重链的结构改变。
