scholarly journals Collagen heterogeneity within different growth regions of long bones of rachitic and nonrachitic chicks

1972 ◽  
Vol 127 (4) ◽  
pp. 715-720 ◽  
Author(s):  
Bryan P. Toole ◽  
Andrew H. Kang ◽  
Robert L. Trelstad ◽  
Jerome Gross
Keyword(s):  
Vitamin D ◽  
Amino Acid ◽  
Bone Matrix ◽  
Bone Collagen ◽  
Long Bone ◽  
Long Bones ◽  
Collagen Structure ◽  
Collagen Molecules ◽  
Relationship Of ◽  
Chain Type

The different anatomical regions involved in osteogenesis in the chick long bone have been examined for heterogeneities in collagen structure that might relate to the mechanism of ossification. Experimentally induced lathyrism was employed to enhance collagen solubility, and vitamin D deficiency to allow accumulation of osteoid, the precursor of bone matrix. The extractable lathyritic collagens of the cartilaginous and osseous regions of growing long bones from rachitic and non-rachitic chicks were examined for α-chain type and amino acid composition. In both groups of animals the growth plate and cartilaginous regions of the epiphysis gave collagen molecules of the constitution [α1(II)]3, whereas the ossifying regions contained [α1(I)]2 α2. The degree of hydroxylation of the lysine moieties was increased by approximately 50% in the α1(I)-chain and α2-chain of rachitic bone collagen. Since uncalcified osteoid is greatly enriched in rachitic bone, it is concluded that the collagen of osteoid has the configuration [α1(I)]2 α2, similar to that of bone matrix, but has an elevated hydroxylysine content. The possible relationship of this difference to the mechanism of calcification is discussed.

scholarly journals Identification of organic phosphorus covalently bound to collagen and non-collagenous proteins of chicken-bone matrix. The presence of O-phosphoserine and O-phosphothreonine in non-collagenous proteins, and their absence from phosphorylated collagen

1979 ◽  
Vol 177 (1) ◽  
pp. 81-98 ◽  
Author(s):  
Lola Cohen-Solal ◽  
Jane B. Lian ◽  
Dora Kossiva ◽  
Melvin J. Glimcher
Keyword(s):  
Amino Acid ◽  
Glutamic Acid ◽  
Proteinase Inhibitors ◽  
Organic Phosphorus ◽  
Bone Matrix ◽  
Bone Collagen ◽  
Insoluble Residue ◽  
Cationic Amino Acid ◽  
Chicken Bone ◽  
Covalently Bound

Non-collagenous phosphoproteins, almost all of which can be extracted in EDTA at neutral pH in the presence of proteinase inhibitors, are identified in the matrix of chicken bone, and are therefore not covalently bound to collagen. Similarly, all the peptides containing γ-carboxyglutamic acid are present in the EDTA extract and none in the insoluble residue, confirming that none is covalently linked to chicken bone collagen. However, organic phosphorus is also found to be present in chicken bone collagen, principally in the α2-chains. Of the total protein-bound organic phosphorus present in chicken bone matrix, approx. 80% is associated with the non-collagenous proteins and 20% with collagen. The soluble non-collagenous proteins contain both O-phosphoserine and O-phosphothreonine and these account for essentially of their organic phosphorus content. In contrast, collagen contains neither O-phosphoserine nor O-phosphothreonine. Indeed, no phosphorylated hydroxy amino acid, phosphoamidated amino acid or phosphorylated sugar could be identified in purified components of collagen, which contain approximately four to five atoms of organic phosphorus per molecule of collagen. Peptides containing organic phosphorus were isolated from partial acid hydrolysates and enzymic digests of purified collagen components, which contain an as-yet-unidentified cationic amino acid. These data, the very high concentrations of glutamic acid in the phosphorylated peptides, and the pH-stability of the organic phosphorus moiety in intact collagen chains strongly suggest that at least part of the organic phosphorus in collagen is present as phosphorylated glutamic acid. This would indicate that the two major chemically different protein fractions in chicken bone matrix that contain organic phosphorus may represent two distinct metabolic pools of organic phosphorus under separate biological control.

scholarly journals Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Takashi Matsuura ◽  
Kentaro Tokutomi ◽  
Michiko Sasaki ◽  
Michitsuna Katafuchi ◽  
Emiri Mizumachi ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Matrix Protein ◽  
Relative Strength ◽  
Bone Collagen ◽  
Long Bone ◽  
Osteogenic Potential ◽  
Lower Amount ◽  
Long Bones ◽  
Distinctive Features ◽  
Lysine Hydroxylation

Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

scholarly journals EFFECTS OF INSULIN-LIKE GROWTH FACTOR TYPE I ON BONE REMODELING IN PHYSIOLOGICAL PREGNANCY AND NORMAL LEVELS OF VITAMIN D

2012 ◽  
Vol 15 (3) ◽  
pp. 14-17
Author(s):  
D S Sudakov ◽  
T V Novikova ◽  
O S Bibkova ◽  
O V Galkina ◽  
I E Zazerskaya
Keyword(s):  
Vitamin D ◽  
Bone Remodeling ◽  
Bone Matrix ◽  
Type I ◽  
Long Bones ◽  
Distal Forearm ◽  
Igf I ◽  
Moderate Negative Correlation ◽  
Factor Type ◽  
Moderate Positive Correlation

During pregnancy the levels of IGF-I increase and in III trimester exceed greatly the values of I trimester. Its significant increase is noted from 22-24 weeks of pregnancy. Correlation analysis revealed a moderate negative correlation between the level of IGF-I in II trimester and distal forearm BMD (r = -0,35, p<0,5). Also a moderate positive correlation between the level of IGF-I and a marker of bone synthesis osteocalcin in the II and III trimesters of pregnancy was revealed (r = 0,46, p <0,05 and r = 0,41, p<0,05, respectively). Conclusions: IGF-I effects bone remodeling of long bones during pregnancy. It is probable that under the influence of IGF-I synthesis of bone matrix is increased, which in the presence of low calcium intake may be associated with reduced BMD at these bone sites.

Rescue diet restores bone matrix mineralization in mice with a non-functioning vitamin D receptor

2019 ◽  
Author(s):  
Barbara Misof ◽  
Stephane Blouin ◽  
Markus Hartmann ◽  
Jochen Hofstaetter ◽  
Klaus Klaushofer ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Bone Matrix ◽  
Matrix Mineralization ◽  
Bone Matrix Mineralization

Diabetes and osteoporosis

2011 ◽  
Vol 152 (29) ◽  
pp. 1161-1166 ◽  
Author(s):  
Zsuzsanna Valkusz
Keyword(s):  
Vitamin D ◽  
Type 1 Diabetes ◽  
Bone Mass ◽  
Fragility Fractures ◽  
Vitamin D Supplementation ◽  
Bone Collagen ◽  
Skeletal Changes ◽  
Glucagon Like Peptide 1 ◽  
Bone Quantity

Over the last decades a considerable amount of data has accumulated to indicate that metabolic and endocrine alterations of diabetes affect bone quantity and quality. These skeletal changes may increase the risk of bone fracture. There is strong evidence that in type 1 diabetes the decreased bone mass, lack of insulin and insulin-like growth factor-1, dysregulation of adipokines, and increased levels of proinflammatory cytokines are in the background of fragility fractures. In type 2 diabetes hyperinsulinemia, insulin resistance and increased body weight may result in an increase of bone mass; however, accumulation of advanced glycation end products within the bone collagen driven by glucotoxicity may increase the cortical porosity. There is a higher incidence of falls resulting from diabetes-related co-morbidities such as diabetic retinopathy, peripheral neuropathy, hypoglycemic episodes and sometimes from the medications. Vitamin D deficiency has special impact on glucose metabolism and the prevalence of diabetes. Vitamin D supplementation in childhood can decrease incidence of type 1 diabetes by 80%. The effect of thiazolidinediones, glucagon-like peptide-1 agonists and metformin, agents for treatment of diabetes open a new connection between bone, carbohydrate and fat metabolism. Orv. Hetil., 2011, 152, 1161–1166.

Collagen-the Ultrastructural Element of the Bone Matrix

2018 ◽  
Vol 69 (7) ◽  
pp. 1706-1709
Author(s):  
Nicoleta Dumitru ◽  
Andra Cocolos ◽  
Andra Caragheorgheopol ◽  
Constantin Dumitrache ◽  
Ovidiu Gabriel Bratu ◽  
...  
Keyword(s):  
Type I Collagen ◽  
Bone Microarchitecture ◽  
Complex Structure ◽  
Bone Matrix ◽  
Organic Matrix ◽  
Bone Diseases ◽  
Bone Collagen ◽  
Type I ◽  
New Therapeutic Approaches ◽  
And Function

There is an increased interest and more studies highlight the fact that bone strength depends not only on bone tissue quantity, but also on its quality, which is characterized by the geometry and shape of bones, trabecular bone microarchitecture, mineral content, organic matrix and bone turnover. Fibrillar type I collagen is the major organic component of bone matrix, providing form and a stable template for mineralization. The biomedical importance of collagen as a biomaterial for medical and cosmetic purposes and the improvement of the molecular, cellular biology and analytical technologies, led to increasing interest in establishing the structure of this protein and in setting of the relationships between sequence, structure, and function. Bone collagen crosslinking chemistry and its molecular packing structure are considered to be distinct features. This unique post-translational modifications provide to the fibrillar collagen matrices properties such as tensile strength and viscoelasticity. Understanding the complex structure of bone type I collagen as well as the dynamic nature of bone tissues will help to manage new therapeutic approaches to bone diseases.

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