scholarly journals Contrasting Local and Macroscopic Effects of Collagen Hydroxylation

2021 ◽  
Vol 22 (16) ◽  
pp. 9068
Author(s):  
Sameer Varma ◽  
Joseph P. R. O. Orgel ◽  
Jay D. Schieber
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonding ◽  
Local Structure ◽  
Triple Helix ◽  
Type I Collagen ◽  
Chemical Change ◽  
Fibrillar Structure ◽  
Minor Effect ◽  
Type I ◽  
Macroscopic Properties

Collagen is heavily hydroxylated. Experiments show that proline hydroxylation is important to triple helix (monomer) stability, fibril assembly, and interaction of fibrils with other molecules. Nevertheless, experiments also show that even without hydroxylation, type I collagen does assemble into its native D-banded fibrillar structure. This raises two questions. Firstly, even though hydroxylation removal marginally affects macroscopic structure, how does such an extensive chemical change, which is expected to substantially reduce hydrogen bonding capacity, affect local structure? Secondly, how does such a chemical perturbation, which is expected to substantially decrease electrostatic attraction between monomers, affect collagen’s mechanical properties? To address these issues, we conduct a benchmarked molecular dynamics study of rat type I fibrils in the presence and absence of hydroxylation. Our simulations reproduce the experimental observation that hydroxylation removal has a minimal effect on collagen’s D-band length. We also find that the gap-overlap ratio, monomer width and monomer length are minimally affected. Surprisingly, we find that de-hydroxylation also has a minor effect on the fibril’s Young’s modulus, and elastic stress build up is also accompanied by tightening of triple-helix windings. In terms of local structure, de-hydroxylation does result in a substantial drop (23%) in inter-monomer hydrogen bonding. However, at the same time, the local structures and inter-monomer hydrogen bonding networks of non-hydroxylated amino acids are also affected. It seems that it is this intrinsic plasticity in inter-monomer interactions that preclude fibrils from undergoing any large changes in macroscopic properties. Nevertheless, changes in local structure can be expected to directly impact collagen’s interaction with extra-cellular matrix proteins. In general, this study highlights a key challenge in tissue engineering and medicine related to mapping collagen chemistry to macroscopic properties but suggests a path forward to address it using molecular dynamics simulations.

scholarly journals Structure-property-function relationships in triple-helical collagen hydrogels

2012 ◽  
Vol 1498 ◽  
pp. 145-150 ◽  
Author(s):  
Giuseppe Tronci ◽  
Amanda Doyle ◽  
Stephen J. Russell ◽  
David J. Wood
Keyword(s):  
Triple Helix ◽  
Type I Collagen ◽  
Molecular Organization ◽  
Type I ◽  
Tissue Formation ◽  
Structure Property ◽  
Mineralized Tissue ◽  
Mineral Deposition ◽  
Collagen Hydrogels ◽  
Macroscopic Properties

ABSTRACTIn order to establish defined biomimetic systems, type I collagen was functionalised with 1,3-Phenylenediacetic acid (Ph) as aromatic, bifunctional segment. Following investigation on molecular organization and macroscopic properties, material functionalities, i.e. degradability and bioactivity, were addressed, aiming at elucidating the potential of this collagen system as mineralization template. Functionalised collagen hydrogels demonstrated a preserved triple helix conformation. Decreased swelling ratio and increased thermo-mechanical properties were observed in comparison to state-of-the-art carbodiimide (EDC)-crosslinked collagen controls. Ph-crosslinked samples displayed no optical damage and only a slight mass decrease (∼ 4 wt.-%) following 1-week incubation in simulated body fluid (SBF), while nearly 50 wt.-% degradation was observed in EDC-crosslinked collagen. SEM/EDS revealed amorphous mineral deposition, whereby increased calcium phosphate ratio was suggested in hydrogels with increased Ph content. This investigation provides valuable insights for the synthesis of triple helical collagen materials with enhanced macroscopic properties and controlled degradation. In light of these features, this system will be applied for the design of tissue-like scaffolds for mineralized tissue formation.

A Continuous-Discrete Finite Element Model of Angiogenesis That Couples Vessel Growth With Matrix Deformation

2013 ◽  
Author(s):  
Lowell T. Edgar ◽  
Steve A. Maas ◽  
James E. Guilkey ◽  
Jeffrey A. Weiss
Keyword(s):  
Type I Collagen ◽  
Three Dimensional ◽  
Collagen Gel ◽  
Element Model ◽  
Fibrillar Structure ◽  
Type I ◽  
Major Pathway ◽  
Vessel Growth ◽  
Discrete Finite Element

Recent developments in tissue engineering have created demand for the ability to create microvascular networks with specific topologies in vitro. During angiogenesis, sprouting endothelial cells apply traction forces and migrate along components of the extracellular matrix (ECM), resulting in neovessel elongation [1]. The fibrillar structure of the ECM serves as the major pathway for mechanotransduction between contact-dependent cells. Using a three-dimensional (3D) organ culture model of microvessel fragments within a type-I collagen gel, we have shown that subjecting the culture to different boundary conditions during angiogenesis can lead to drastically different vascular topologies [2]. Fragments cultured in a rectangular gel that were free to contract grew into a randomly oriented network [3, 4]. When the long-axis of the gel was constrained as to prevent contraction, microvessels and collagen fibers were found aligned along the constrained axis (Fig. 1) [4].

scholarly journals Structural Heterogeneity of Type I Collagen Triple Helix and Its Role in Osteogenesis Imperfecta

2007 ◽  
Vol 283 (8) ◽  
pp. 4787-4798 ◽  
Author(s):  
Elena Makareeva ◽  
Edward L. Mertz ◽  
Natalia V. Kuznetsova ◽  
Mary B. Sutter ◽  
Angela M. DeRidder ◽  
...  
Keyword(s):  
Osteogenesis Imperfecta ◽  
Triple Helix ◽  
Type I Collagen ◽  
Structural Heterogeneity ◽  
Type I ◽  
Collagen Triple Helix

scholarly journals Hydroxylation of Type I Collagen: Effects on Fibrillar Structure and Mechanics

2019 ◽  
Vol 116 (3) ◽  
pp. 457a-458a
Author(s):  
Alekhya A. Kandoor ◽  
Michele Kirchner ◽  
Vered Wineman-Fisher ◽  
Yujia Xu ◽  
Sameer Varma
Keyword(s):  
Type I Collagen ◽  
Fibrillar Structure ◽  
Type I

scholarly journals The Characteristics of Intrinsic Fluorescence of Type I Collagen Influenced by Collagenase I

2018 ◽  
Vol 8 (10) ◽  
pp. 1947 ◽  
Author(s):  
Yiming Shen ◽  
Deyi Zhu ◽  
Wenhui Lu ◽  
Bing Liu ◽  
Yanchun Li ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Self Assembly ◽  
Triple Helix ◽  
Type I Collagen ◽  
Intrinsic Fluorescence ◽  
Type I ◽  
Food And Agriculture ◽  
Mechanism Research ◽  
Helix Structure ◽  
Assembly Behavior

The triple helix structure of collagen can be degraded by collagenase. In this study, we explored how the intrinsic fluorescence of type I collagen was influenced by collagenase I. We found that tyrosine was the main factor that could successfully excite the collagen fluorescence. Initially, self-assembly behavior of collagen resulted in a large amount of tyrosine wrapped with collagen, which decreased the fluorescence intensity of type I collagen. After collagenase cleavage, some wrapped-tyrosine could be exposed and thereby the intrinsic fluorescence intensity of collagen increased. By observation and analysis, the influence of collagenase to intrinsic fluorescence of collagen was investigated and elaborated. Furthermore, collagenase cleavage to the special triple helix structure of collagen would result in a slight improvement of collagen thermostability, which was explained by the increasing amount of terminal peptides. These results are helpful and effective for reaction mechanism research related to collagen, which can be observed by fluorescent technology. Meantime, the reaction behaviors of both collagenase and collagenolytic proteases can also be analyzed by fluorescent technology. In conclusion, this research provides a foundation for the further investigation of collagen reactions in different areas, such as medicine, nutrition, food and agriculture.

Specific osteogenesis imperfecta-related Gly substitutions in type I collagen induce distinct structural, mechanical, and dynamic characteristics

2021 ◽  
Author(s):  
Haoyuan Shi ◽  
Liming Zhao ◽  
Chenxi Zhai ◽  
Jingjie Yeo
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonds ◽  
Osteogenesis Imperfecta ◽  
Dynamic Characteristics ◽  
Type I Collagen ◽  
Type I ◽  
Vibrational Modes ◽  
Wild Type ◽  
Triple Helices ◽  
Dynamics Simulations

The stiffnesses, β-structures, hydrogen bonds, and vibrational modes of wild-type collagen triple helices are compared with osteogenesis imperfecta-related mutants using integrative structural and dynamic analysis via molecular dynamics simulations and...

Type V collagen synthesis and deposition by chicken embryo corneal fibroblasts in vitro

1989 ◽  
Vol 94 (2) ◽  
pp. 371-379
Author(s):  
J.S. McLaughlin ◽  
T.F. Linsenmayer ◽  
D.E. Birk
Keyword(s):  
Collagen Synthesis ◽  
Type I Collagen ◽  
Fibrillar Structure ◽  
Type I ◽  
Homogeneous Population ◽  
Type V Collagen ◽  
Total Collagen ◽  
Corneal Fibroblasts ◽  
Type V

Chick embryo corneal fibroblasts were grown in culture to study the processes whereby fibroblasts regulate the deposition and organization of the collagenous, secondary stroma. The effects of an existing type I collagen substratum, cell density, and serum concentration on type V collagen synthesis were investigated. Type V collagen represented approximately 20% of the total fibrillar collagen synthesized, regardless of whether the cells were subcultured, grown on untreated or collagen-coated plastic, grown under confluent or subconfluent conditions, or grown in the presence of low (0.1%) or high (10.0%) serum concentrations. The synthesis of type V collagen remained constant at 20% of the total collagen when cells were grown in 1.0% serum, even though total collagen synthesis increased nearly twofold when compared to total synthesis in 0.1% or 10.0% serum. Immunocytochemistry with anti-collagen, type-specific monoclonal antibodies revealed a homogeneous population of cells synthesizing types I and V collagen. The fibrils deposited by cells grown in a three-dimensional collagen matrix contained a helical epitope on the type V molecule that was inaccessible unless the fibrillar structure was disrupted, mimicking the situation in situ. The production in vitro of heterotypic fibrils, with a constant I/V ratio and molecular packing mimicking the natural stroma, offers opportunities for studying in more detail this important process, which is essential for optical transparency.

Advances Toward Forming Synthetic Mimetic Tendon

MRS Advances ◽  
2016 ◽  
Vol 1 (18) ◽  
pp. 1283-1288
Author(s):  
Dilinazi Aishanjiang ◽  
Emily C. Green ◽  
Heng Li ◽  
Marilyn L. Minus
Keyword(s):  
Type I Collagen ◽  
Fibrillar Structure ◽  
Type I ◽  
Structural Development ◽  
Collagen Gels ◽  
Connective Tissues ◽  
Synthetic Fibers ◽  
Spinning Process ◽  
Bovine Type

ABSTRACTCollagen is the most abundant protein present in the human body and found in connective tissues, bone, and tendon. It is also known as a natural resource for healing damaged skin tissues [1]. In this study, under specific microenvironment conditions, mimetic collagen gels were successfully formed synthetically from reconstituted Bovine type I collagen monomers. This was achieved by controlling ionic strength, temperature and pH, allowing fibrils with native mimetic D periodic banding structure to assemble spontaneously within the gels. In addition, by providing appropriate aging temperatures and times, mature collagen fibril growth is also realized in the gels in vitro. Mimetic gels were subsequently formed into fibers through a wet-spinning process. These spun fibers were found to preserve the native mimetic D periodic banding and fibrillar structure formed in the initial gels. As a result, the synthetic fibers resemble native tendon. Here structural development within the gel samples and fibers as a function of processing was analyzed by scanning electron microscopy (SEM). Results in this study also show a potentially new route for the fabrication of synthetic collagen fibers mimicking tendon, which may find applications as engineered tissues or scaffolding materials.

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