STRUCTURE OF HEXAMERIC BUNDLES OF BETA-AMINO ACID PEPTIDE U1F

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。U1F: b3glu - b3leu - b3orn - b3ph - b3leu - b3asp - b3ph - b3leu - b3orn - b3orn - b3leu - b3asp其中b3Xxx为与α -氨基酸Xxx的同基化产物相对应的3取代β -氨基酸。Orn =鸟氨酸。我们合成了一种β -氨基酸十二肽U1F，它在水中协同折叠形成稳定的同六聚体。通过核磁共振氘交换实验和圆二色性测量对其折叠进行了表征。通过超离心分析，确定其在溶液中的低聚态为六聚体。我们已经获得了在我们的家乡来源（耶鲁结构生物学中心）衍射约3埃的晶体。我们将空间群分配给P42212，单元格尺寸为43 X 43 X 75埃。这与含有六聚体U1F束的细胞一致。在CHESS上，我们希望获得明显更高分辨率的衍射数据，目前受晶体尺寸和光源强度的限制。我们正在筛选衍生品，以便在我们的国内来源上分阶段进行，也可能带来确认的衍生品，以进行高分辨率数据收集。六聚体U1F是由非天然-氨基酸组成的分子中三元结构的第一个例子。U1F也很重要，因为它是最小的（12mer）四元结构之一，自然或非自然，显示合作折叠转变。U1F被设计成折叠和寡聚基于从β肽二级结构和亮氨酸拉链三元结构的研究收集的原则。合理设计的折叠聚合物代表了我们对自然（即蛋白质）和非自然系统中控制折叠的力的理解的重要证明。因此，我们期望U1F的高分辨率结构将引起化学和生物界的广泛兴趣。Petersson博士在加州理工学院Dennis Dougherty的实验室通过合成氨基酸结合研究蛋白质结构和功能获得博士学位。丹尼尔斯博士在斯克里普斯的约翰·泰纳实验室通过x射线晶体学研究DNA修复酶获得博士学位。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. U1F: b3Glu-b3Leu-b3Orn-b3Phe-b3Leu-b3Asp-b3Phe-b3Leu-b3Orn-b3Orn-b3Leu-b3Asp where b3Xxx refers to the 3-substituted beta-amino acid corresponding to the homoligation product of alpha-amino acid Xxx. Orn = ornithine. We have synthesized U1F, a beta-amino acid dodecapeptide, which folds cooperatively to form a stable homohexamer in water. Its folding has been characterized by deuterium exchange NMR experiments and circular dichroism measurments. Its oligomeric state in solution was assigned to be a hexamer by analytical ultracentrifugation. We have obtained crystals which diffract to approximately 3 angstroms on our home source (Yale Center for Structural Biology). We have assigned the space group to P42212 and the unit cell dimensions to 43 X 43 X 75 angstroms. This is consistent with a unit cell containing a hexameric U1F bundle. At CHESS, we hope to obtain significantly higher resolution diffraction data, which is currently limited by crystal size and source intensity. We are screening derivatives for phasing on our home source and may also bring confirmed derivatives for high resolution data collection. The hexameric U1F represents the first example of ternary structure in a molecule composed of unnatural beta-amino acids. U1F is also significant because it is one of the smallest (12mer) quaternary structures, natural or unnatural, to display a cooperative folding transition. U1F has been designed to fold and oligomerize based on principles gleaned from studies of beta-peptide secondary structure and leucine zipper ternary structure. Rationally designed folded polymers represent an important demonstration of our understanding of the forces which govern folding in both natural (i.e. protein) and unnatural systems. Therefore, we expect that a high resolution structure of U1F will be of great general interest to both the chemistry and biology communities. Dr. Petersson received his Ph.D. studying protein structure and function through synthetic amino acid incorporation in the labs of Dennis Dougherty at Caltech. Dr. Daniels received his Ph.D. studying DNA repair enzymes through x-ray crystallography in the labs of John Tainer at Scripps.