Collagen is the most abundant single organic component of connective tissue. The maturation of collagen, that is the formaton of covalent crosslinks between and among collagen chains, is critical to its stability and function in a tissue. We know that the most abundant crosslink (DHLNL) is type I collagens from two different tissues, tendon and dentin, has different, molecular distributions. The distinct crosslink distributions must be related to functional differences in the collagens from these diverse tissues, but few studies have addressed this important problem Crosslink maturation is altered in bone collagen from chicks with the bone tumor, osteoblastoma. Bones are hypomineralized and birds grow at a decreased rate. The purpose of this study is to learn how a dietary deficiency such as food restriction or hypocalcemia, or the presence of disease, such as avian osteogenic osteoblastoma affect bone mineralization and the distribution of collagen crosslinks with development. The specific aims of this proposal involve quantitatiion of pyridinoline and NaB3H4-reducible sugar-free and glycosylated crosslinks by amino acid analysis, and determination of the distribution of crosslinks in collagen tryptic peptides after chromatographic separation from bone collagen of normal; osteoblastoma and restricted diet chicks. Utilizing a new method, I will determine the quantity and distribution of crosslinks in nonmineralized versus mineralized collagen. This will be the first study of its kind to investigate normal developmental changes in the distribution of collagen crosslinks, as well as how distribution is affected by diet and disease. These experiments will relate the structure and function of collagen with the mineralization process, and reveal how diet and disease alter the normal relationships. The long term objective is to elucidate the molecular basis for the pathology of collagen maturation in developmental disorders.