MECHANOSENSITIVE PROTEINS--A MOLECULAR STUDY IN E COLI

所有的细胞生物体都会对振动、触摸、重力或 渗透压，但这种机械感觉的分子基础是 未知。候选分子包括某些离子通道，例如 大肠杆菌的机械敏感甚大电导通道(MSCL) 用膜片钳实验观察到。我们使用了功能测试来 鉴定MSCL为L7-KD蛋白，并克隆了相应的基因MSCL。 该序列显示了一个由136个氨基酸组成的独特蛋白质，高度 疏水性，富含P结构。我们计划在中国找到MSCL的同源基因 其他物种，并确定受保护的区域。然后我们将生成 嵌合体和定点突变体以及要定义的选定突变体 负责溶质的氨基酸残基或多肽区域 渗透性和机械敏感性。通过结合重组DNA 技术和膜片钳分析，我们希望了解分子 这种独特的机械敏感蛋白的结构/功能关系。

All cellular organisms respond to vibration, touch, gravity, or changes in osmolarity, but the molecular bases of such mechano-sensations are unknown. Candidate molecules include certain ion channels, such as the mechano-sensitive channel of very large conductance (MscL) of Escherichia coli observed by patch-clamp experiments. We used a functional test to identify MscL as a l7-kD protein and cloned the corresponding gene, mscL. The sequence indicates a unique protein of 136 amino acid, highly hydrophobic, and rich in P structure. We plan to find mscL homologues in other species and to define the conserved regions. We will then generate chimeras and site-directed mutants as well as selected mutants to define the amino-acid residues or peptide regions responsible for solute permeability and mechano-sensitivity. By combining recombinant DNA technology and patch-clamp analysis, we hope to understand the molecular structure/function relation of this unique mechanosensitive protein.