MUROPEPTIDE RECYCLING PATHWAY & BETA LACTAMASE INDUCTION

胞肽回收途径

• 批准号: 6072734
• 负责人: JAMES T PARK
• 金额: $ 5.43万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6072734
• 关键词: Escherichia coli; N acetylglucosaminidase; amidases; bacterial proteins; beta lactamase; cell wall; enzyme biosynthesis; enzyme induction /repression; glycopeptides; high performance liquid chromatography; microorganism metabolism; permease

The principal objectives of this proposal are to elucidate the pathway used by E. coli for recycling muropeptides, to determine the function recycling serves in the life of the cell and to characterize the role of muropeptides in the beta-lactamase induction process. These objectives follow from our preliminary results which support the following tentative conclusions: (1) AmpG, which is required for beta-lactamase induciton, is a permease required for recycling cell wall components. (2) AmpG most likely transports N-acetylglucosaminyl-beta 1-4, 1,6 anhydro-N-acetylmuramyl-L- alanyl-D-glutamyl-(L)-meso-diaminopimelic acid (G1cNAc-anhMurNAc-L-ala-D- glu-DAP) into the cytoplasm. (3) AmpD, required for beta-lactamase inducibility is also essential for recycling. (4) ampD mutants accumulate huge amounts of anhMurNAc-L-ala-D-glu-DAP indicating that it is an inducing ligand. (5) AmpD is an anhMurNAc-1-ala amidase. Presumably the tripeptide released by the AmpD amidase is added to UDPMurNAc by a yet to be discovered tripeptide-adding enzyme thereby reintroducing L-ala-D-glu- DAP into the biosynthetic pathway. (6) G1cNAc-anhMurNAC-L-ala-D-glu-DAP is probably another inducer of beta-lactamase. Thus, based on these new results of the past 16 months, the specific aims are: 1. To study and characterize the 4 predicted steps in the recycling pathway, namely: AmpG permease, beta-N-acetylglucosaminidase, AmpD amidase, and the hypothetical tripeptide-adding enzyme. 2. To identify the muropeptides involved in beta-lactamase induction and to further characterize their role in beta-lactamase induction. 3. To search for a role of recycling in the life of the cell.

该提案的主要目标是阐明所使用的途径 通过大肠杆菌进行回收杂肽，以确定功能回收利用 在细胞的生活中发挥作用，并表征杂肽的作用 在β-内酰胺酶诱导过程中。 这些目标来自我们 支持以下初步结论的初步结果：（1） AMPG是β-内酰胺酶诱导剂所需的AMPG，是份 回收细胞壁成分所需。 （2）AMPG很可能 运输N-乙酰葡萄糖氨基-Beta 1-4，1,6饮用 乙酰基-D-谷氨酸（L） - 米索二氨基二酰胺酸（G1CNAC-ANHMURNAC-L-ALA-D-） glu-dap）进入细胞质。 （3）AMPD，β-内酰胺酶必需 诱导性对于回收也是必不可少的。 （4）AMPD突变体积累 大量的anhmurnac-l-ala-d-d-d-glu-dap表明它是诱导的 配体。 （5）AMPD是ANHMURNAC-1-ALA酰胺酶。 大概是 由AMPD amidase释放的三肽被添加到UDPMurnac中 被发现是添加三肽的酶，从而重新引入L-Ala-d-Glu- DAP进入生物合成途径。 （6）G1CNAC-ANHMURNAC-L-ALA-D-GLU-DAP 可能是β-内酰胺酶的另一个诱导剂。 因此，基于这些新的 过去16个月的结果，具体目的是： 1。研究和表征回收的4个预测步骤 途径，即：AMPG粘酶，β-N-乙酰葡萄糖胺酶，AMPD amidase，以及假想的三肽添加酶。 2。确定参与β-内酰胺酶诱导和 进一步表征它们在β-内酰胺酶诱导中的作用。 3。寻找在细胞生命中回收的作用。