IN VITRO FOLDING AND ASSEMBLY OF MHC MOLECULES

该项目的目的是了解分子机制 控制MHC-I类分子的组装和折叠。 的 MHC I类分子作为关键的细胞表面结构， 用于抗原识别的细胞内肽片段样品- 特异性MHC限制性T淋巴细胞。 在这个项目中，我们寻求 在体外系统中了解这三种成分是如何 由MHC I类分子、合成肽、 而轻链亚基β 2-微球蛋白从线性 肽链，正确折叠和生物活性的MHC 分子。 通过改造天然存在的单链类似物， MHC分子，其中每个组分都是同一分子的一部分。 多肽链，我们已经产生了有效的模型系统， I类分子的体外折叠。 我们的研究结果表明， I类分子应被视为三聚体，其中每个组分 链起着关键作用的途径，以适当的三维 结构 此外，缺乏中间结构的证据 肽组分，并且在血清学和功能上可区分 从天然三聚体，已经获得。 这些研究不仅可以 我们更好地了解MHC I类分子和方法， 它的工程变体，而且还增加了我们对 蛋白质折叠及其与蛋白质功能的关系。

The aim of this project has been to understand the molecular mechanisms that control the assembly and folding of the MHC class I molecules. The MHC class I molecules serve as the critical cell surface structures that sample intracellular peptide fragments for recognition by antigen- specific, MHC-restricted T lymphocytes. In this project we have sought to understand in an in vitro system how the components of this three chain structure consisting of MHC class I molecule, synthetic peptide, and the light chain subunit, beta2-microglobulin proceed from linear peptide chains, to a properly folded and biologically active MHC molecule. By engineering single chain analogs of the naturally occuring MHC molecules in which each of the components is part of the same polypeptide chain, we have produced model systems for the efficient in vitro folding of class I molecules. Our results indicate that the MHC class I molecule should be considered as a trimer in which each component chain plays a critical role in the pathway to a proper three-dimensional structure. In addition, evidence for an intermediate structure lacking the peptide component, and serologically and functionally distinguishable from the native trimer, has been acquired. Such studies not only permit us to better understand the MHC class I molecule and approaches for engineering variants of it, but also increase our basic understanding of protein folding and its relationship to protein function in general.