Mechanistic studies of PHB biosynthesis

描述（由申请人提供）：聚羟基烷酸酯（PHAs）是一类微生物聚酯，由许多细菌产生，作为细胞内碳和能量储存聚合物。它们展示了从热塑性塑料到弹性体的各种材料特性。pha的一个重要特性是其在各种环境或生物系统中的固有生物降解性。因此，希望以环保和经济上具有竞争力的方式用可生物降解的塑料取代传统的石化塑料，这推动了这个项目。这种新型工程材料有望在心脏瓣膜和组织工程支架等领域得到广泛应用。本提案的长期目标是确定和了解PHA生物合成及其调控的机制。具体来说，为了区分聚羟基丁酸酯（PHBs）形成的两种延伸机制，将采用化学方法结合突变酶的构建来捕获聚合中间体。晶体结构将大大增强对延伸机理的理解，有助于更合理地设计基于机理的抑制剂。然而，迄今为止，虽然取得了一些进展，但尚未获得PHB合酶的晶体。将制备和探索一系列化合物作为合酶的共价抑制剂，并通过诱变方法获得它们的晶体。pha是普遍感兴趣的，因为它们具有从热塑性塑料到弹性体的各种性能，并且是可生物降解的。了解PHA的生物合成对于设计新材料至关重要，这些新材料目前正在研究其在心脏瓣膜和组织工程支架中的应用。本项目的目标是识别和了解PHA生物合成及其调控机制。

DESCRIPTION (provided by applicant): Polyhydroxyalkanoates (PHAs) are a class of microbial polyesters produced by many bacteria as intracellular carbon and energy storage polymers. They display material properties ranging from thermoplastics to elastomers. An important characteristic of PHAs is their inherent biodegradability in various environments or biosystems. Thus, the desire to replace the conventional petrochemical-based plastics with biodegradable plastics in an environmentally friendly and economically competitive fashion has served an impetus for this project. The new engineered materials are expected find wide applications such as in heart valves and as scaffolds for tissue engineering. The long-term goal of this proposal is to identify and understand the machinery involved in PHA biosynthesis and its regulation. Specifically, in order to distinguish between the two elongation mechanisms proposed for the formation of polyhydroxybutyrates (PHBs), approaches involving chemical methods, in combination with the construction of mutant enzymes, to trap the polymerization intermediates will be employed. Crystal structures will greatly enhance the understanding of the elongation mechanism and help design mechanism-based inhibitors more rationally. However, to date, no crystals of PHB synthases have been obtained although some progress has been made. A series of compounds will be prepared and explored as covalent inhibitors of synthases in an effort to obtain their crystals along with mutagenetic methods. PHAs are of general interest as they possess properties that range from thermoplastics to elastomers and are biodegradable. Understanding the PHA biosynthesis is crucial to engineering new materials that are currently being examined for their applications such as in heart valves and as scaffolds for tissue engineering. The goal of this project is to identify and understand the machinary involved in PHA biosynthesis and its regulation.