FUNCTIONAL ANALYSIS OF MAIZE GROUP-1 POLLEN ALLERGENS

玉米 1 类花粉过敏原的功能分析

• 批准号: 6228399
• 负责人: DANIEL J COSGROVE
• 金额: $ 19.22万
• 依托单位: PENNSYLVANIA STATE UNIVERSITY, THE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-12-15 至 2004-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6228399
• 关键词: X ray crystallography; airborne allergen; angiosperms; biochemical evolution; biotransformation; cell wall; chemical kinetics; corn; crystallization; glycoprotein biosynthesis; immunofluorescence technique; mass spectrometry; nonblood rheology; plant growth /development; plant morphology; pollen; protein isoforms; protein localization; protein protein interaction; protein structure function; serial analysis of gene expression; site directed mutagenesis; video microscopy

DESCRIPTION (from the application): When grass pollen lands on the receptive surface of the stigma, it begins to hydrate and secrete various proteins. Among these is an antigenic protein known as the group-I grass pollenallergen. This protein is a major cause of hay fever and asthma, afflicting ca. 25 percentof the US population. We recently discovered that the group-I allergen from maize pollen (called Zea ml) loosens the extracellular matrix (wall) of the grass stigma. In this proposal, we outline several experimental approaches to elucidate the structure, function, and evolutionary distribution of the group-I allergens and related proteins, which we hypothesize aid pollen tube penetration of the stigma and style. RNA and protein analyses will be used to determine the temporal and spatial pattern of Zea ml expression and secretion. Using a reverse genetics approach we have identified four maize lines with transposon insertions in the Zea ml gene; these lines will be studied to learn the phenotypic consequences of Zea ml gene disruption. We will take advantage of the unusual physical properties of Zea ml to study how it acts to loosen the cell wall, still an enigmatic problem. By X-ray analysis of Zea ml crystals, we propose to solve its structure and to use this structure to investigate how the protein interacts with the polymers of the extracellular matrix. By binding assays we will define the substrates to which this protein binds. We will test these ideas by site-directed mutagenesis of recombinant protein. We will also attempt to identify peptides, monoclonal antibodies and oligosaccharides that interfere with Zea ml activity, to be used as inhibitors of the biological function of these proteins. To date, it appears that group-I grass pollen allergens are found only in grasses. To evaluate the evolutionary distribution of this protein, we will test pollen extracts from grasses, close relatives, and more distant plant groups by means of activity and immunoblot assays. Finally, we will leverage the insights gained from analysis of Zea ml to study the function of group-Il and group-Ill grass pollen allergens, which show significant sequence similarity with the carboxy terminus of group-I allergens.

描述(来自应用程序)：当草花粉落在接受器上时 在柱头表面，它开始水合并分泌各种蛋白质。其中 这是一种被称为I组草花粉变应原的抗原性蛋白。这 蛋白质是花粉热和哮喘的主要原因，大约25%的人患有这种疾病 美国人口。我们最近发现，来自玉米的I组过敏原 花粉(称为玉米粉)松散了草的细胞外基质(壁)。 耻辱。在这份提案中，我们概述了几种实验性的方法 阐明G-I的结构、功能和进化分布 过敏原和相关蛋白质，我们假设它们有助于花粉管 穿透了耻辱和风格。RNA和蛋白质分析将用于 确定ZEA ML表达和分泌的时空模式。 利用反向遗传学方法，我们已经鉴定了四个玉米品系 转座子插入玉米M1基因；这些品系将被研究以了解 ZEA m1基因破坏的表型后果。我们会利用这个优势 来研究它是如何起到松弛 细胞壁，仍然是一个谜。通过对ZEA-ML晶体的X射线分析，我们发现 提出解决它的结构，并用这个结构来研究 蛋白质与细胞外基质的聚合物相互作用。通过装订 分析表明，我们将定义这种蛋白质结合的底物。我们将测试 这些想法是通过重组蛋白的定点突变实现的。我们还将 尝试鉴定多肽、单抗和寡糖 干扰玉米白粉菌活性，用作生物抑制剂 这些蛋白质的功能。到目前为止，似乎第一类草的花粉 过敏原只在草中发现。评估进化分布 在这种蛋白质中，我们将测试从草，近亲， 和更远的植物类群通过活性和免疫印迹分析。 最后，我们将利用从ZEA ML分析中获得的见解来研究 草本植物花粉变应原的功能 与I组变应原的羧基末端有显著的序列相似性。