The antigenic determinants on HIV p24 for CD4+ T cell inhibiting antibodies as determined by limited proteolysis, chemical modification, and mass spectrometry.
The antigenic determinants on HIV p24 for CD4+ T cell inhibiting antibodies as determined by limited proteolysis, chemical modification, and mass spectrometry.
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通过有限的蛋白水解、化学修饰和质谱测定，CD4 T 细胞抑制抗体的 HIV p24 上的抗原决定簇。
DOI：
10.1016/j.jasms.2006.06.011
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发表时间：
2006
影响因子：
3.2
通讯作者：
Norris,PhilipJ
中科院分区：
文献类型：
--
作者：
Williams,JasonG;Tomer,KennethB;Hioe,CatarinaE;Zolla-Pazner,Susan;Norris,PhilipJ
在过去的十年里，越来越多的研究人员使用质谱学来鉴定大分子复合体中的蛋白质以及确定它们的结合界面的表面。除了实际的质谱学之外，蛋白质-蛋白质界面的这种表征通常还包括几种不同方法中的至少一种。例如，当感兴趣的蛋白质是大分子复合体的一部分时，有限的蛋白质分解通常被用作定义蛋白质区域的第一步，这些区域被保护而不被蛋白质分解。与质谱学结合使用的用于确定蛋白质与蛋白质相互作用的蛋白质区域的其他技术包括化学修饰，如共价交联、赖氨酸的乙酰化、氢-氚交换或其他形式的修饰。在这份报告中，有限的蛋白质降解和化学修饰与几种质谱学技术相结合，努力确定HIV核心蛋白p24上的蛋白质表面，这是由从HIV+患者分离的两种不同的人类单抗识别的。其中一种抗体1571强烈抑制CD4+T细胞对已知表位(PEVIPMFSALSEGATP)的增殖反应，而另一种抗体241-D则没有那么强的抑制作用。这两种抗体的表位都被确定为不连续的，并定位在p24的N端。有趣的是，强抑制抗体1571识别的表位与T细胞表位PEVIPMFSALSEGATP完全重叠，而抗体241-D与抗体1571识别的p24区域相邻的区域结合。这些结果表明，可能由于表位竞争，HIV感染过程中产生的抗体可以对CD4+T细胞介导的针对病毒的免疫产生负面影响。
In the last decade, mass spectrometry has been employed by more and more researchers for identifying the proteins in a macromolecular complex as well as for defining the surfaces of their binding interfaces. This characterization of protein-protein interfaces usually involves at least one of several different methodologies in addition to the actual mass spectrometry. For example, limited proteolysis is often used as a first step in defining regions of a protein that are protected from proteolysis when the protein of interest is part of a macromolecular complex. Other techniques used in conjunction with mass spectrometry for determining regions of a protein involved in protein-protein interactions include chemical modification, such as covalent cross-linking, acetylation of lysines, hydrogen-deuterium exchange, or other forms of modification. In this report, both limited proteolysis and chemical modification were combined with several mass spectrometric techniques in efforts to define the protein surface on the HIV core protein, p24, recognized by two different monoclonal human antibodies that were isolated from HIV+patients. One of these antibodies, 1571, strongly inhibits the CD4+T cell proliferative response to a known epitope (PEVIPMFSALSEGATP), while the other antibody, 241-D, does not inhibit as strongly. The epitopes for both of these antibodies were determined to be discontinuous and localized to the N-terminus of p24. Interestingly, the epitope recognized by the strongly inhibiting antibody, 1571, completely overlaps the T cell epitope PEVIPMFSALSEGATP, while the antibody 241-D binds to a region adjacent to the region of p24 recognized by the antibody 1571. These results suggest that, possibly due to epitope competition, antibodies produced during HIV infection can negatively affect CD4+T cell-mediated immunity against the virus.