BIOCHEMISTRY OF CYSTIC FIBROSIS MUCOUS SECRETIONS

粘液粘弹性异常的存在 气管支气管树是患者最广为人知的特征 囊性纤维化(CF)。这会导致肺气道阻塞。 并导致慢性肺部疾病，这是导致大部分 慢性阻塞性肺疾病患者的死亡率。这项研究计划的目标是 探讨碳纤维粘弹性能改变的基础 分泌物。具体目标是a)确定更改后的 纤维支气管壁分泌物的粘弹性与 生化成分的变化(例如，硫酸盐化水平的增加 与正常粘蛋白相比的CF粘蛋白)或具有生物物理变化 粘蛋白分子的性质(例如，分子聚集特性 和粘蛋白构象)和b)确定非粘蛋白成分的作用 存在于分泌物中，如血清蛋白(尤其是白蛋白， 溶菌酶、免疫球蛋白等)和聚阳离子[钙、多胺(腐胺， 精胺和精胺)和低分子碱性蛋白(S)] 粘蛋白的分子聚集和粘弹性性质。为了这些 研究表明，天然和还原的粘蛋白和非粘蛋白成分将是 从a)CF患者的气管、支气管分泌物中提纯；b) 年龄和性别匹配的正常对照组，包括CF的正常兄弟姐妹 患者和c)年龄和性别匹配的支气管炎和哮喘患者， 使用本实验室建立的协议。生化 提纯成分的表征将包括：测定 碳水化合物，硫酸盐，氨基酸组成，二硫键含量， 各组分的相对电荷和相对分子质量。用于生物物理 CF和对照分泌物的纯化成分的表征， 我们将使用荧光探针来确定疏水结合部位 粘蛋白和其他组分的技术和分子聚集 高灵敏度和多功能的荧光偏振和光 散射技术。光散射将用来确定 粘蛋白和粘蛋白聚集体的分子量，以及 确定粘蛋白分子的构象(即从回转半径 决心)。粘弹性属性将使用 磁力显微测速仪。这些研究将有助于理解 异常粘弹性能的内在机制(S) CF分泌物。此外，从研究中获得的知识将有助于 慢性肺病合理治疗方法的研究进展 最终必须具备控制粘弹性的能力 分泌物的性质、分泌物的速率和清除。

The presence of mucous secretions with abnormal viscoelastic properties of the tracheobronchial tree is the most widely known feature of patients with cystic fibrosis (CF). This results in the obstruction of the lung airways and leads to chronic pulmonary disease which is responsible for most of the mortality in CF patients. The objectives of this research proposal are to investigate the basis of altered viscoelastic properties of the CF secretions. The specific objectives are a) to determine if the altered viscoelastic properties of CF tracheobronchial secretions correlate with changes in the biochemical composition (e.g., increased level of sulfation of CF mucin as compared to normal mucin) or with changes in biophysical properties of mucin molecules (e.g., molecular aggregation characteristics and mucin conformation) and b) determine the effect of non-mucin components present in the secretions, such as serum proteins (especially albumin, lysozyme, IgG, etc.), and polycations [Ca2+, polyamines (putrescine, spermidine and spermine) and low molecular weight basic proteins(s)] on the molecular aggregation and viscoelastic properties of the mucins. For these studies, the native and reduced mucin and non-mucin components will be purified from tracheobronchial secretions collected from a) CF patients; b) age and sex matched normal controls including normal siblings of CF patients and c) age and sex matched patients with bronchitis and asthma, using protocols established in this laboratory. Biochemical characterization of purified components will include: determination of carbohydrate, sulfate, amino acid composition, disulfide bond content, relative charge and molecular weight of the components. For biophysical characterization of the purified components of CF and control secretions, we will determine hydrophobic binding sites using fluorescence probe technique and molecular aggregation of mucins and other components using highly sensitive and versatile fluorescence polarization and light scattering techniques. Light scattering will be used to determine molecular weight of mucins, and of mucin aggregates as well as for determining conformation of mucin molecules (i.e. from radius of gyration determination). The viscoelastic properties will be determined using a magnetic microrheometer. These studies will aid in the understanding of underlying mechanism(s) responsible for abnormal viscoelastic properties of the CF secretions. Also, knowledge from studies will facilitate the development of a rational approach to the treatment of chronic lung disease in CF which ultimately must require an ability to control the viscoelastic properties, rate of secretion and elimination of the secretions.