STABILITY AND FOLDING OF BPTI WITH UNNATURAL CROSSLINKS

牛胰胰蛋白酶抑制剂（BPTI）是一种58个残基的小分子蛋白质 有三个二硫键 BPTI已广泛用于蛋白质 折叠研究表明，折叠途径通过以下途径进行： 含有特定二硫键的中间体。 任何一个的形成 二硫化物将稳定缓慢交换的核心，并开始折叠， 使完全伸展的展开形式不稳定。 我们的假设，我们 试图通过全合成来测试，任何自然或非自然的交叉- 不引入不利应变的链接，将具有相同的 效果 一种类型的交联是使BPTI环化，其可以是 这是可能的，因为在BPTI的溶液结构中， 在三维空间中是紧密相连的 具体目标是 建议是合成和表征循环排列的变体 BPTI和具有非天然交联的类似物。 这项工作将提供 关于BPTI中二硫桥作用的明确结论 折叠和稳定性，并预计将导致显着的见解， 有助于我们理解正确管理的关键因素 蛋白质的折叠

Bovine pancreatic trypsin inhibitor (BPTI) is a 58-residue small protein with three disulfide bridges. BPTI has been used extensively in protein folding studies, which suggest that the folding pathway proceeds via intermediates containing specific disulfide bonds. Formation of any one disulfide will stabilize the slow-exchange core and initiate folding by destabilizing the fully extended unfolded form. Our hypothesis, which we seek to test by total synthesis, is that any natural or unnatural cross- link that does not introduce unfavorable strain, will have the same effect. One type of cross-link is to circularize BPTI, which may be possible because in the solution structure of BPTI, the N- and C-termini are in close three-dimensional proximity. The specific aims of this proposal are to synthesize and characterize circularly permuted variants of BPTI and analogues with unnatural cross-links. This work will provide definitive conclusions about the roles of disulfide bridges in BPTI folding and stability and is expected to lead to significant insights that contribute to our understanding of the critical factors governing proper folding of proteins.