Kinetics of Intracellular Protein Degradation in Bacteria

细菌细胞内蛋白质降解动力学

• 批准号: 8721973
• 负责人: James Bailey
• 金额: $ 27.28万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-15 至 1992-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8721973&HistoricalAwards=false
• 关键词: Kinetics; Intracellular; Protein; Degradation; Bacteria

Degradation of proteins within bacteria is an ongoing regulated process, which in concert with protein synthesis processes, determines the protein make-up of the cell and thus its transport and reaction properties. Under conditions of nutrient limitation, which are common to many bioprocesses or in genetically engineered cells, intracellular protein degradation rates are greatly accelerated. Intracellular protein breakdown contributes significantly to maintenance nutrient requirements in many bioprocess contexts and to loss of product yield in recombinant fermentations. This research will seek engineering kinetic descriptions of intracellular protein degradation, which can be used to guide organism and process design to maximize growth and product yields. In particular, this research will provide key data which are needed to improve kinetic models for bacterial growth and product synthesis under different growth conditions. This research addresses a central technical limitation in the manufacture of biochemicals, such as insulin and amino acids. After being synthesized within a genetically engineered cell, a protein product such as insulin is frequently attached and decomposed by digestive enzymes within that cell. Similarly, cells used to produce amino acids lose their capability to produce because critical proteins in those cells are inactivated by those cells' internal digestive enzymes. This research will study these degradative processes and how their rates might be reduced by careful choice of bioprocess operating conditions, such as temperature. Also, various genetic changes in the cell, which reduce its internal digestive activities, will be investigated to minimize productivity loses. The results of this research will be guidance of the genetic engineer and the biochemical engineer on ways to improve the useful production lifetime of the bioprocess. This lifetime is often a critical factor in successful process economic performance.

细菌内蛋白质的降解是一个持续的调节过程， 过程，与蛋白质合成过程一致， 决定了细胞的蛋白质组成， 和反应性质。 在营养条件下 限制，这是常见的许多生物过程或 基因工程细胞，细胞内蛋白质降解 速度大大加快。 细胞内蛋白质分解 显著有助于维持营养需求， 许多生物工艺环境和产品产量的损失， 重组发酵。 这项研究将寻求工程 细胞内蛋白质降解的动力学描述， 可用于指导生物和工艺设计，以最大限度地 增长和产品产量。 特别是，这项研究将 提供关键数据，需要改进动力学模型， 不同生长条件下的细菌生长和产物合成 条件 这项研究解决了一个核心的技术限制， 生产生物化学品，如胰岛素和氨基酸。 在基因工程细胞中合成后， 蛋白质产品如胰岛素经常附着在 被细胞内的消化酶分解 与此类似， 用于生产氨基酸的细胞失去了 因为这些细胞中的关键蛋白质被灭活了 由这些细胞内部的消化酶消化。 这项研究将 研究这些降解过程以及它们的速率 通过仔细选择生物工艺操作条件而减少， 例如温度。 此外，细胞中的各种遗传变化， 减少其内部消化活动， 以尽量减少生产力损失。 的结果 研究将指导基因工程师和 生物化学工程师如何提高有用的生产 生物过程的生命周期。 这一生往往是一个关键 成功的工艺经济性能的因素。