CONFORMATIONALLY CONSTRAINED PROTEIN POLYMERS

构象受限蛋白质聚合物

• 批准号: 6518854
• 负责人: KENT W KIRSHENBAUM
• 金额: $ 1.24万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6518854
• 关键词: alkenes; aminoacid analog; biotechnology; chemical models; conformation; methionine; peptide chemical synthesis; polymers; protein engineering; protein structure; structural biology; synthetic protein; thermostability

The proposed research will entail the design, modeling, synthesis, and characterization of repeating polypeptide sequences incorporating non-natural amino acids. A particular emphasis will be the in vivo expression of protein polymers that include the methionine analog homoallylglycine, or "Hag". The presence of the alkene chemical functionality in these polymers will be exploited to create novel macromolecular materials with tailored properties. Artificial genes encoding alpha-helical protein polymers that include Hag residues in a repeating i to i + 4 pattern will be expressed in an E. coli methionine auxotroph. Following purification, the terminal alkene groups of the Hag sidechains will be subjected to ring-closing metathesis. This reaction will generate 19-membered ring macrocycles that will tether the protein secondary structure. The anticipated product is a monodisperse rigid-rod polymer. The biophysical and materials properties of this polymer will be investigated, with particular attention to the thermal stability of the alpha- helical structure. The behavior of the polymers will be modeled by molecular dynamics simulations. Characterization of these polymers will provide advances in materials science through the precise spatial patterning of novel chemical functionalities, and will provide advances in protein biophysics through an enhanced understanding of the forces that control the formation of protein secondary structure.

拟议的研究将需要设计，建模，合成和表征的重复多肽序列纳入非天然氨基酸。 一个特别的重点将是蛋白质聚合物的体内表达，包括蛋氨酸类似物高烯丙基甘氨酸，或“Hag”。 这些聚合物中烯烃化学官能团的存在将被利用来创造具有定制特性的新型大分子材料。 编码α-螺旋蛋白质聚合物的人工基因将在大肠杆菌中表达，所述α-螺旋蛋白质聚合物包括重复i至i + 4模式的Hag残基。大肠杆菌蛋氨酸营养缺陷型。纯化后，Hag侧链的末端烯烃基团将进行闭环复分解。 该反应将产生19元环大环，其将束缚蛋白质二级结构。 预期产物是单分散刚性棒聚合物。 将研究这种聚合物的生物物理和材料性质，特别注意α-螺旋结构的热稳定性。 聚合物的行为将通过分子动力学模拟来建模。 这些聚合物的表征将提供材料科学的进步，通过精确的空间图案化的新的化学功能，并将提供蛋白质生物物理学的进步，通过加强理解的力量，控制蛋白质二级结构的形成。