MATRIX CONTROL OF BIOMINERALIZATION

这项研究的目的是为了对 有机基质通过研究控制生物矿化的机制 生物化学、物理化学和结构方面的 胶原蛋白矿化。酸性大分子的能力 诱导矿物形成和控制矿物生长，以及 胶原蛋白结构对矿物定位和生长模式的影响 将会被检查。胶原蛋白、矿物质之间的结构关系 和多阴离子以及胶原交联物的变化和 与过渡相关的三维纤维结构 钙化火鸡腿中非矿化到矿化的胶原蛋白 肌腱将被详细介绍。结果将提供基本信息 关于生物矿化的机制；必不可少的信息 到开发治疗基本骨骼疾病的方法，其中Matix控制 可能会丢失，如骨质疏松症和骨化症。的能力 固定化酸性大分子诱导矿物将被确定 从矿物质诱导时间和生长速度的恒定 组成恒化器，以便对动力学进行比较 基础。基质的控制将通过将 聚阴离子与三种基因不同的胶原蛋白：I、II和X型。 矿物生长的控制将通过确定特定于面部的 荧光标记聚阴离子在羟基磷灰石上的吸附 晶体及其吸附对藻类生长和习性的影响 水晶。这一控制也将用聚阴离子诱导 恒化器中的矿物质形成。晶体的类型、它们的和 具有胶原蛋白结构的聚阴离子的定位将由 使用特定的电子显微镜(EM)成像技术， 电子衍射、图像分析和三维层析重建。 这些EM技术以及特定的组织化学染色和免疫标记 将被用来确定胶原纤维之间的关系 结构、矿物质、蛋白多糖和其他多阴离子，并比较 外部非矿化部分在内部的差异 火鸡腿部肌腱的矿化部分，并确定 肌腱内侧部分在从未矿化的 导致矿化基质中I型胶原结构的变化 在火鸡腿部肌腱从非矿化向矿化转变过程中 矿化基质将通过量化分子来研究 共价分子间交联链的分布及其相互作用 胶原蛋白纤维中的前体醛。这将通过以下方式完成 这些化合物的定量分析及其含量的测定 通过从纤维中分离这些肽来定位纤维内的分子位点 氚化硼氢化钠-还原组织。从这些数据中， 胶原纤维的特殊三维结构变化 将会衍生出与矿化有关的矿化。少校 这种组织中的磷蛋白，潜在的矿化核素， 将使用离子交换分离和表征 层析、磷酸盐和氨基酸分析。

The objective of this research is to obtain a basic understanding of the mechanisms by which organic matrix controls biomineralization by studying the biochemical, physicochemical and structural aspects of the mineralization of collagen. The capacities of acidic macromolecules to induce mineral formation and to control mineral growth, and effects of collagen structure on localization and growth patterns of the mineral will be examined. The structural relationships between collagen, mineral and polyanions and changes in the collagen cross-links and three-dimensional fibrillar structure associated with the transition from non-mineralized to mineralized collagen in the calcifying turkey leg tendon will be detailed. The results will provide basic information about the mechanisms of biomineralization; information that is essential to developing therapies for basic skeletal disorders where matix control may be lost, such as osteoporosis and osteopetrosis. The capacities of immobilized acidic macromolecules to induce mineral will be determined from the mineral induction times and growth rates in a constant composition chemostat so that the comparisons are made on a kinetic basis. Control by the substrate will be investigated by attaching the polyanions to three genetically different collagens; types I, II, and X. Control of mineral growth will be examined by determining face-specific adsorption of fluorescently labelled polyanions onto hydroxyapatite crystals and the effect of this adsorption on the growth and habits of the crystals. This control also will be examined with polyanionicinduced mineral formation in a chemostat. The crystal types, their and the polyanions' localization with collagen structure will be determined by the use of specific electron microscopic (EM) imaging techniques, electron diffraction, image analysis, and 3D tomographic reconstruction. These EM techniques and specific histochemical stains and immunolabelling will be used to determine relationships between collagen fibrillar structure, mineral, proteoglycans and other polyanions and to compare the differences between the outer non-mineralizing portion in the inner mineralizing portion of turkey leg tendon and to determine changes in the inner portion of the tendon during the transition from a non-mineralized to a mineralized matrix Changes in the structure of the type I collagen in turkey leg tendon during the transition from a non-mineralized to a mineralized matrix will be studied by quantifying the molecular distribution of the covalent intermolecular cross-links and their precursor aldehydes in the collagen fibrils. This will be done by quantitative analysis of these compounds and determination of their molecular loci within the fibril by isolating these peptides from the tritiated sodium borohydride-reduced tissue. From this data, the specific three-dimensional structural changes of collagen fibrils associated with mineralization will be derived. The major phosphoproteins of this tissue, potential nucleators for mineralization, present will be isolated and characterized using ion exchange chromatography and phosphate and amino acid analyses.