Stuctural studies of triple-helical proteins

三螺旋蛋白质的结构研究

• 批准号: 7923559
• 负责人: BARBARA M BRODSKY
• 金额: $ 15.34万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7923559
• 关键词: Amino Acid Sequence; Architecture; Basement membrane; Binding; Biocompatible Materials; Biological; Biological Process; Cell Surface Receptors; Classification; Collagen; Collagen Diseases; Collagen Fibril; Collagen Type IV; Collagen Type VII; Complement; Degenerative polyarthritis; Dermal; Development; Disease; Electrostatics; Enzymes; Extracellular Matrix; Fibrillar Collagen; Foundations; Glycine; Hereditary Disease; Higher Order Chromatin Structure; Hydration status; Hydrophobic Interactions; Hydroxyproline; Interruption; Lateral; Lead; Length; Link; Malignant Neoplasms; Mechanics; Mediating; Missense Mutation; Modeling; Molecular; Molecular Conformation; Molecular Structure; Morphology; Non-Fibrillar Collagens; Pathology; Pattern; Peptides; Pharmaceutical Preparations; Play; Predisposition; Process; Proteins; Rheumatologic Disorder; Role; Site; Structure; Structure-Activity Relationship; Testing; Tissues; Vertebral column; base; decaglycine; design; flexibility; matrigel; protein aminoacid sequence; retinal rods; small molecule; triple helix

DESCRIPTION (provided by applicant): Collagen is the most abundant protein in the body, defined by its unique triple-helical conformation and repeating sequence pattern with glycine as every third residue. Biophysical studies are proposed to relate the (Gly-X-Y)n amino acid sequence and breaks in this pattern with molecular features and higher order structure of collagens, which are directly related to their function and pathology. Our studies on the classic triple helix will be extended to characterization of the consequences of natural breaks in the (Gly-X-Y)n pattern found in non-fibrillar collagens, such as type IV collagen in basement membranes and type VII collagen that mediates dermal-epidermal attachment. The effects of the length and sequence of such breaks on triple-helix stability, folding and conformation will be investigated using model peptides. To complement peptide studies, flexibility, folding and enzyme susceptibility will be examined on an expressed bacterial product where a break is introduced between two tandem triple-helix modules. These studies will provide information about the structural consequences of breaks and their biological role. The association of collagen molecules to higher order structures is essential to their mechanical and biological function. The relation between sequence, the process of triple-helix association to higher order structures, and the morphology of the final product will be defined. Studies will be carried out to further characterize non- specific lateral assembly observed for collagen peptides and to introduce electrostatic and hydrophobic residues in peptide sequences to produce more specific axial interactions and defined higher order structures. Small natural breaks in the (Gly-X-Y)n repeat appear to put flanking triple-helix regions out of register, and their impact on self-association will be investigated. Gly missense mutations in fibrillar and non-fibrillar collagen lead to a variety of hereditary diseases. The folding, stability, hydrodynamic and conformational consequences of Gly missense mutations will be characterized in peptides and in an expressed bacterial construct. In non-fibrillar collagens, it is hypothesized that missense mutations interfere with the renucleation mechanism needed to fold through natural breaks. Definition of the fundamental principles of collagen triple-helix molecular structure and association into higher order structures will further our understanding of normal matrix structure/function relationships and enhance the development of collagen-based biomaterials. In addition, it will provide a basis for defining extracellular matrix alterations in disease and for developing drugs which could inhibit the breakdown of collagens in cancer and osteoarthritis.

描述（由申请人提供）：胶原蛋白是体内最丰富的蛋白质，由其独特的三螺旋构象和每三个残基为甘氨酸的重复序列模式定义。生物物理学研究建议将（Gly-X-Y）n氨基酸序列和这种模式中的断裂与胶原蛋白的分子特征和高级结构联系起来，这与它们的功能和病理学直接相关。我们对经典三螺旋的研究将扩展到表征在非纤维性胶原蛋白中发现的（Gly-X-Y）n模式中的自然断裂的后果，如基底膜中的IV型胶原蛋白和介导真皮-表皮附着的VII型胶原蛋白。将使用模型肽研究这种断裂的长度和序列对三螺旋稳定性、折叠和构象的影响。为了补充肽的研究，灵活性，折叠和酶的敏感性将被检查的表达的细菌产品，其中一个中断是两个串联的三螺旋模块之间引入。这些研究将提供有关断裂的结构后果及其生物学作用的信息。胶原蛋白分子与更高级结构的结合对其机械和生物功能至关重要。序列之间的关系，三螺旋协会的过程中，以更高的顺序结构，和最终产品的形态将被定义。将进行研究以进一步表征观察到的胶原蛋白肽的非特异性侧向组装，并在肽序列中引入静电和疏水残基以产生更特异性的轴向相互作用和确定的更高级结构。（Gly-X-Y）n重复序列中的小的自然断裂似乎会使侧翼三螺旋区域失去记录，将研究它们对自缔合的影响。纤维状和非纤维状胶原蛋白中的Gly错义突变导致多种遗传性疾病。Gly错义突变的折叠、稳定性、流体动力学和构象后果将在肽和表达的细菌构建体中表征。在非纤维状胶原中，假设错义突变干扰通过自然断裂折叠所需的再成核机制。胶原蛋白三螺旋分子结构的基本原理的定义和更高层次的结构协会将进一步我们的正常基质结构/功能关系的理解和促进胶原蛋白为基础的生物材料的发展。此外，它将为确定疾病中细胞外基质的变化和开发能够抑制癌症和骨关节炎中胶原分解的药物提供基础。