UV Spectroscopic Characterization of Type I Collagen

Na, George C.

doi:10.1016/s0174-173x(88)80003-7

Cited by 38 publications

(23 citation statements)

References 34 publications

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“…It is believed that this is due to partial cleavage of non-helical telopeptides (13,14,31). The observed decrease in the number of tyrosines/ molecule from ϳ10 in AcCol to ϳ5 in PepCol supports this interpretation, as previously shown (26).…”

Section: Resultssupporting

confidence: 84%

“…However, the ordering of collagen molecules in reconsti- a The values were obtained using a 1500 M Ϫ1 cm Ϫ1 extinction coefficient for Tyr at 275.5 nm, as described (24). For type I collagen, this spectroscopic method agrees with direct amino acid analysis within ϳ10% (25,26). In our case, the most likely source of error was base-line subtraction.…”

Section: Resultssupporting

confidence: 67%

“…24. For type I collagen, it was shown previously that this spectroscopic method agrees with direct amino acid analysis within ϳ10% (25,26).…”

Section: Methodsmentioning

confidence: 55%

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Does the Triple Helical Domain of Type I Collagen Encode Molecular Recognition and Fiber Assembly while Telopeptides Serve as Catalytic Domains?

Kuznetsova¹,

Leikin

1999

Journal of Biological Chemistry

108

104

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Over the last several decades, it has been established that proteolytic removal of short, non-helical terminal peptides (telopeptides) from type I collagen significantly alters the kinetics of in vitro fibrillogenesis. However, it has also been observed that the protein is still capable of forming fibers even after complete removal of telopeptides. This study focuses on the characterization of this fibrillogenesis competency of collagen. We have combined traditional kinetic and thermodynamic assays of fibrillogenesis efficacy with direct measurements of interaction between collagen molecules in fibers by osmotic stress and x-ray diffraction. We found that telopeptide cleavage by pepsin or by up to 20 h of Pronase treatment altered fiber assembly kinetics, but the same fraction of the protein still assembled into fibers. Small-angle x-ray diffraction showed that these fibers have normal, native-like D-stagger. Force measurements indicated that collagen-collagen interactions in fibers were not affected by either pepsin or Pronase treatment. In contrast, prolonged (>20 h) Pronase treatment resulted in cleavage of the triple helical domain as indicated by SDS-polyacrylamide gel electrophoresis. The triple-helix cleavage correlated with the observed decrease in the fraction of protein capable of forming fibers and with the measured loss of attraction between helices in fibers. These data suggest that telopeptides play a catalytic role, whereas the information necessary for proper molecular recognition and fiber assembly is encoded in the triple helical domain of collagen.Type I collagen is a major component of the extracellular matrix in all higher vertebrates, e.g. it is the main structural protein of skin, bone, and tendon (see, for example, Refs. 1 and 2). Each molecule is a heterotrimer composed of two ␣1(I) chains and one ␣2(I) chain. It contains a long triple helical domain (ϳ1000 residues from each chain) and short, non-helical terminal peptides (telopeptides).In vitro, under appropriate conditions, type I molecules spontaneously form fibers that are virtually indistinguishable from native fibers by electron microscopy (see, for example, Ref.3).X-ray diffraction patterns from such reconstituted fibers and from native fibers are similar as well (4 -7). It is commonly believed that type I collagen contains all structural information that is necessary for its self-assembly into fibers, except maybe for some tissue-specific factors (see, for example, Ref. 8). However, the location of the "coding" regions, the nature of this information, and how it is "translated" into intermolecular forces responsible for fibrillogenesis are still poorly understood.One of the debated issues is the role of telopeptides. Telopeptides form covalent cross-links with triple helical regions on opposing molecules (see, for example, Refs. 9 and 10). It is believed that this occurs after completion of fibrillogenesis and that the cross-links stabilize rather than create appropriate molecular arrangement. It was also suggested that telopept...

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Section: Resultssupporting

confidence: 84%

Section: Resultssupporting

confidence: 67%

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Does the Triple Helical Domain of Type I Collagen Encode Molecular Recognition and Fiber Assembly while Telopeptides Serve as Catalytic Domains?

Kuznetsova¹,

Leikin

1999

Journal of Biological Chemistry

108

104

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“…Collagen solubility was measured by optical absorbance of the supernatant. A calibration curve was determined by measuring optical absorbance at 215-230 nm [14] (USB2000, Ocean Optics, Dunedin, Fl) of a series of known collagen solutions at different concentrations. Our previous study used optical absorbance at 276 nm to measure collagen concentration in solution [9].…”

Section: Collagen Fibril Formation and Solubilitymentioning

confidence: 99%

Correlation between collagen solubility and skin optical clearing using sugars

et al. 2007

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Background and Objective: Light scattering from collagen within skin limits light-based therapeutics while increasing the risk of epidermal thermal injury. Specific chemicals show the ability to reduce light scattering by reversibly altering the optical properties of skin. This study examines the correlation between collagen solubility and the optical clearing potential (OCP) of sugars and sugar-alcohols using in vitro rodent skin. Materials and Methods: Collagen solubility in dextrose, fructose, sucrose, and sorbitol was measured using near-UV spectroscopy. Light transmittance, reflectance, and rodent skin thickness were measured (giving skin reduced scattering coefficient) before and after exposure of the dermal surface to sugars and sugar-alcohols. OCP was calculated as the ratio of reduced scattering coefficients before and after exposures. Results: Dextrose, fructose, sucrose, and sorbitol had at least twice the collagen solubility and twice the OCP as compared to glycerol. In general, collagen solubility correlated with each agent's ability to optically clear rodent skin.Conclusion: These results demonstrate that sugar and sugar-alcohol interaction with collagen are a primary event in tissue optical clearing.

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“…The CD spectra of type I collagen treated by different concentration of procyanidin were shown in Figure 2. For the case of natural type I collagen, specific peaks in far ultraviolet (UV) region at 222nm and 197nm can be observed on CD spectrum, which were due to n to π* transition of polyproline II ring and π to π* transition, respectively (27,(30)(31)(32). Shown as Figure 2, the absorption bands on CD spectrum (curve a) were typical peaks of collagen type I, which indicated that the secondary structure of collagen kept well.…”

Section: Circular Dichroism (Cd) Studiesmentioning

confidence: 92%

A Reconsideration of the Effect of Procyanidin on the Assembly of Collagen Type I

Wang

Jin

2018

Preprint

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In order to elucidating the exact effect mechanism of polyphenols on the assembly of collagen, the assembled architectures of collagen treated with different amounts of procyanidin (PA) were investigated in details. The assembled morphologies of collagen were greatly influenced by the content of PA according to atomic force microcopy (AFM) images.When the content of PA was more than 20% (w/w), the fibrillar morphologies were substituted by globular aggregates, which were driven by the intense hydrogen bonding action originating from PA. While the formation of the non-fibrous aggregates was due to the coiling and entangling of flexible collagen molecules rather than their gelatinization based on the appearance of typical adsorption peaks at 222nm and 197nm on circular dichroism (CD) spectra. After being crosslinked by glutaraldehyde (GA), not only the diameters but also the lengths of fibrils increased. Unfortunately, the fibrillogenesis was still inhibited when the collagen suffered from 20% PA firstly and then 4% GA. Conversely, the fibrous morphologies of the fibrils stabilized by 4% GA and then underwent 20% PA maintained well, in spite of accompanying with grievous intertwining. This difference was derived from the change of flexibilities of collagen before and after being crosslinked by GA. Additionally, the differential scanning calorimeter (DSC) analysis confirmed the PA had no positive effect on the improvement of thermal stability of hydrous collagen, whereas the denaturation temperature of hydrated collagen stabilized by 4% GA increased from 40 °C to 80 °C.

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UV Spectroscopic Characterization of Type I Collagen

Cited by 38 publications

References 34 publications

Does the Triple Helical Domain of Type I Collagen Encode Molecular Recognition and Fiber Assembly while Telopeptides Serve as Catalytic Domains?

Does the Triple Helical Domain of Type I Collagen Encode Molecular Recognition and Fiber Assembly while Telopeptides Serve as Catalytic Domains?

Correlation between collagen solubility and skin optical clearing using sugars

A Reconsideration of the Effect of Procyanidin on the Assembly of Collagen Type I

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