scholarly journals Fourier transform infrared conformational investigation of type I collagen aged by in vitro induced dehydration and non-enzymatic glycation treatments

2017 ◽  
Vol 90 (1) ◽  
Author(s):  
Maria Grazia Bridelli ◽  
Chiaramaria Stani ◽  
Roberta Bedotti
Keyword(s):  
Fourier Transform ◽  
Protein Structure ◽  
Conformational Changes ◽  
Self Assembly ◽  
Type I Collagen ◽  
Protein Secondary Structure ◽  
Fourier Transform Infrared ◽  
Type I ◽  
Absorption Bands

The two main ageing-inducing events in the collagenous tissues are the water loss and the formation of intermolecular crosslinks based on the reaction of collagen with matrix carbohydrates, following a mechanism known as non-enzymatic-glycation. With the aim to mimic the two deleterious processes for the protein structure, rat-tail collagen was submitted to hydration changes and allowed to interact with two sugars characterized by different reducing properties, D-glucose and D-ribose. Fourier transform infrared (FTIR) spectroscopy was employed to investigate the conformational changes induced in the protein by the two treatments by analyzing the subsequent spectra modifications. FTIR spectra monitored: i) the amplitude and position changes of the two characteristic absorption bands OH stretching and Amide I, in dependence on the humidity level: a significant hysteresis effect in the ν(OH) band (ν~3400 cm–1) amplitude of the protein dehydrated and then rehydrated to the initial relative humidity (aw=0.92- 0.06) may be related to the enhancement of the β-sheet fraction in the protein structure as revealed by the parallel modification in the Amide I band (ν~1650 cm–1); ii) the area of the carbohydrate double band peaking at 1080 cm–1 and 1031 cm–1, associated to the accumulation of the glycation products, depending on the sugar concentration and incubation time. The association of both sugars to collagen only minimally affects the protein secondary structure as revealed by Amide I band Gaussian analysis. The whole set of results suggests hints to hypothesize a self-assembly model for collagen molecules induced by ageing.

Structural Differences between Type I and Type IV Collagen in Biological Tissues Studied in vivo by Attenuated Total Reflection/Fourier Transform Infrared Spectroscopy

1992 ◽  
Vol 46 (4) ◽  
pp. 626-630 ◽  
Author(s):  
Yukihiro Ozaki ◽  
Aritake Mizuno ◽  
Fumiko Kaneuchi
Keyword(s):  
Fourier Transform ◽  
Type Iv Collagen ◽  
Type I Collagen ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Random Coil ◽  
Type I ◽  
Type Iv ◽  
Helix Formation

Attenuated total reflection/Fourier transform infrared (ATR/FT-IR) spectra have been obtained in a nondestructive manner for the anterior surface, interior part, and posterior surface of the sclera, for the epithelium, Bowman's membrane, stroma, and endothelium of the cornea, and for the inner section of the Achilles' tendon of a rabbit. The corresponding spectra have been remeasured for the rabbit anterior and posterior lens capsule for purposes of comparison. The spectra of the three parts of the sclera and of the Bowman's membrane and stroma of the cornea are very close to the spectrum of purified type I collagen, confirming that their major components are type I collagen. The spectrum of the tendon is also very similar to that of purified type I collagen, but it contains a small contribution from hyaluronic acid in the 1100-1000 cm−1 region. The amide I bands of the type I collagen-containing tissues are sharp and symmetrical, and their frequencies (1642 cm−1) are almost identical to that (1640 cm−1) of polyglycine II, which takes a 3, helix formation, indicating that the secondary structure of type I collagen in the tissues examined is for practical purposes a slightly modified 31 helix. A comparison of the spectra of the type I collagen-containing tissues and those of the type IV collagen-containing tissues reveals that there are two major differences between them; one is the spectral features in the 1100-1000 cm1 region, where C-O stretching modes of polysaccharide are observed, and the other is the shape and frequency of the amide I band. Besides the peak at 1637 cm−1, the amide I bands of the type IV collagen-containing tissues have shoulders near 1650 and 1655 cm−1. This observation indicates that type IV collagen in the tissues examined assumes primarily a slightly modified 31 helix formation, but the percentages of α-helix and random coil structures are not negligible.

Microaligned collagen matrices by hydrodynamic focusing: controlling the pH-induced self-assembly

2005 ◽  
Vol 898 ◽  
Author(s):  
Sarah Köester ◽  
Jennie B Leach ◽  
Thomas Pfohl ◽  
Joyce Y Wong
Keyword(s):  
Self Assembly ◽  
Type I Collagen ◽  
Polarized Light ◽  
Type I ◽  
Hydrodynamic Focusing ◽  
Microfluidic Mixing ◽  
Ph Gradients ◽  
The Hierarchical Structure ◽  
Local Ph

AbstractThe hierarchical structure of type I collagen fibrils is a key contributor to the mechanical properties of the extracellular matrix (ECM). It is known that the process of in vitro fibrillogenesis strongly depends on the pH of the collagen solution. To date, there are few methods available for precisely controlling and investigating the dependence of collagen fibril assembly on the local pH. The objective of this work was to create highly defined pH gradients to systematically determine the effects of local pH on microscale collagen fibrillogenesis and alignment. We use a microfluidic mixing device to create a diffusion controlled pH gradient, which in turn initiates the self-assembly and concurrent flow-alignment of soluble collagen. Finite element method simulations of the hydrodynamic and diffusive phenomena are used to calculate the local concentrations of the components involved in the reaction. We develop a model to analytically calculate the local pH in the microfluidic device from these concentrations. A comparison with the experimental results from polarized light microscopy are in good agreement with the simulations.

Discontinuous change of the activation energy on Type I collagen in vitro self-assembly.

1999 ◽  
Vol 39 (supplement) ◽  
pp. S165
Author(s):  
I. Someki ◽  
T. Ebihara ◽  
E. Adachi ◽  
S. Hattori ◽  
S. Irie
Keyword(s):  
Activation Energy ◽  
Self Assembly ◽  
Type I Collagen ◽  
Type I ◽  
Discontinuous Change

Production of a Novel, Self-Assembled, Collagenous Matrix Mimicking the Hierarchical Structure of Native Aligned Connective Tissue

1995 ◽  
Vol 414 ◽  
Author(s):  
G. D. Pins ◽  
D. L. Christiansen ◽  
R. Patel ◽  
F. H. Silver
Keyword(s):  
Self Assembly ◽  
Collagen Fiber ◽  
Type I Collagen ◽  
Tensile Tests ◽  
Fiber Formation ◽  
Morphological Properties ◽  
Uniaxial Tensile ◽  
Type I ◽  
Native Collagen

AbstractThe primary goal of the biomaterials scientist and tissue engineer is to create a biocompatible implant which mimics the mechanical and morphological properties of the tissue being replaced. In vitro experimentation has documented the propensity of soluble type I collagen to self-assemble and form microscopic collagen fibrils with periodic banding analogous to native collagen fiber. Our laboratory has further investigated in vitro self-assembly by incorporating several of the “natural” processes into a multi-step fiber formation procedure which generates macroscopic collagen fiber from its molecular constituents. Results of uniaxial tensile tests and ultrastructural analyses indicate that these coextruded and stretched collagen fibers have mechanical properties and fibrillar substructure comparable to that observed in native collagen fiber.

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