CHARACTERIZATION OF THE FC EPSILON RI ALPHA CHAIN BY CRYSTALLOGRAPHY

通过晶体学表征 FC EPSILON RI ALPHA 链

• 批准号: 3746642
• 负责人: J P KINET
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3746642
• 关键词: Escherichia coli; X ray crystallography; antibody receptor; gene mutation; glycoprotein structure; glycosylation; human tissue; immunoglobulin E; ligands; molecular site; nuclear magnetic resonance spectroscopy; receptor binding; transfection

The receptor with high affinity for IgE (Fc(epsilon)RI) is a tetrameric complex of an IgE binding alpha chain, a beta chain and a dimer of gamma chains. In the past we have found that the extracellular region of the alpha chain is solely responsible for ligand binding. In order to further characterize the receptor binding site, we use CHO cells to generate various transfectants secreting the extracellular domain of alpha with the hope of generating crystals for crystallographic analysis. The secreted alpha is active but the heterogenous glycosylation prevents crystallization. Deglycosylation by mutation of the seven N-linked glycosylation sites results in misfolding of the alpha chain in the endoplasmic reticulum of eukaryotic cells. For this reason, we have produced deglycosylated alpha chain in E-Coli. However, the deglycosylated alpha tends to aggregate and therefore is unsuitable for crystallization. Recently, by using limited deglycosylation, we have been able to produce a preparation of alpha chain which is crystallizing. The crystals difract at 4.5 angstrom and are therefore not good enough for standard crystallographic analysis. However, we hope that by adapting the conditions we will be able to produce better crystals.

对IgE具有高亲和力的受体（Fc(epsilon)RI）是一个四聚体