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: 6476569
• 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/6476569
• 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（从应用程序）：当草花粉土地上的接受 在柱头表面，它开始水合并分泌各种蛋白质。之间 这是一种被称为I组草花粉过敏原的抗原蛋白。这 蛋白质是花粉热和哮喘的主要原因，25天 美国人口。我们最近发现玉米中的I类过敏原 花粉（称为玉米）松散的细胞外基质（壁）的草 耻辱在本提案中，我们概述了几种实验方法， 阐明I组的结构、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生长， 柱头和花柱的渗透。RNA和蛋白质分析将用于 确定玉米ml表达和分泌的时间和空间模式。 使用反向遗传学方法，我们鉴定了四个玉米品系， 转座子插入在玉米ml基因;这些线将被研究，以了解 玉米ml基因破坏的表型后果。我们将利用 玉米的不寻常的物理特性，以研究它是如何发挥作用，以放松 细胞壁，仍然是一个谜。通过X射线衍射分析， 建议解决它的结构，并使用此结构来研究如何 蛋白质与细胞外基质的聚合物相互作用。通过结合 我们将确定这种蛋白质结合的底物。我们将测试 这些想法通过重组蛋白的定点突变来实现。我们还将 尝试鉴定肽、单克隆抗体和寡糖， 干扰Zea ml活性，用作生物活性的抑制剂。 这些蛋白质的功能。到目前为止，似乎第一组草花粉 过敏原只存在于草中。为了评估进化分布 这种蛋白质，我们将测试花粉提取物从草，近亲， 和更远的植物群通过活性和免疫印迹测定。 最后，我们将利用从玉米分析中获得的见解来研究 II组和III组草花粉变应原的功能，其显示 与I型过敏原的羧基末端具有显著的序列相似性。