Collagen degradation

ADCOCKS c, COLLIN P and BUTTLE D J (2002) Catechins from green tea Camellia sinensis) inhibit bovine and human cartilage proteoglycan and type 11 collagen degradation in vitro , JNutr, 132 (3), 341-6. 

Yasuda T, Poole AR (2002) A fibronectin fragment induces type II collagen degradation by collagenase through an interleukin-1-mediated pathway. Arthritis Rheum 46(1) 138—148... 

Plaquet et al. (PI) found in the urine of rachitic children peptides consisting of proline, hydroxyproline, and glycine, which they believed to be the products of collagen degradation. Two similar peptides containing considerable amounts of proline and hydroxyproline were isolated from the urine of a patient with rheumatoid arthritis by Mechanic et al. (Ml). One of these peptides consisted of three proline, two hydroxyproline, and nine glutamic acid residues, the second one consisted of four proline, four hydroxyproline, and one glutamic acid residues. The N-terminal amino acid in the first peptide was demonstrated to be hydroxyproline. 

With respect to collagen degradation, two zones can be distinguished within a lesion. The innermost layer is partially demineralized and still recalcifiable, and contains intact collagen fibrils. In the outermost layer, however, the integrity of the fibrils and the capacity for remineralization are lost (Ohgushi and Fusayama, 1975). 

In an in situ study, specimens combining demineralized and mineralized dentin were exposed intraorally (Van Strijp et al., 1997). No correlation was found between demineralization of the mineralized dentin and collagen degradation in the demineralized dentin. 

Preliminary experiments showed that the 18-hour period of collagenase incubation was sufficient for a maximal collagen degradation in the lesions. Samples were taken from all solutions after the incubations to determine the release of calcium from the specimens. For the determi-... 

Once bone diagenesis introduces fissures and causes collagen degradation and mineral recrystallization, these effects become indeed dominant over the small impacts that variations in the bone meso-structure may have on the fluorine uptake. But the initial bone structure steers and controls the specifications of the early diagenesis. Therefore, small variations in the initial bone structure may become very relevant within geological ages. 

In Paget s disease, one observes an increased level of collagen degradation and appearance of hydroxyproline in the urine. 

Bacterial collagenase, however, can be used to digest the interfering collagen degradation products to tripeptides,26 thus revealing the pattern of... 

Hannon et al. (H2) evaluated the response to estrogen substitution therapy after 6 months of treatment by comparing the measurement results with the values before treatment, with respect to the critical differences. The effectiveness of therapy was best followed by the values of osteocalcine and PINP (87% of the results with the drop below the values CD percent). Collagen degradation products U-NTx/Cr and U-CTx/Cr showed only 27% and 18% responses to the treatment, respectively BMD change was significant only for the lumbar spine area in 36% of cases. No answer was reached by measuring the total and femoral value of BMD. 

B7. Bonde, M., Qvist, P., Fledelius, C., Riis, B. J., and Christiansen, C., Immunoassay for quantifying type I collagen degradation products in urine evaluated. Clin. Chem. 40, 2022-2025 (1994). 

K2. Kamel, S., Fardellone, P., Meddal, B., Lorget-Gondelmann, F., Sebert, J. G., and Brazier, M., Response of several markers of bone collagen degradation to calcium supplementation in postmenopausal women with low calcium intake. Clin. Chem. 44, 1437-1442 (1998). 

R5. Robins, S. P., Duncan, A., Wilson, N., and Evans, B. J., Standardization of pyridinium crosslinks, pyridinoline and deoxypyridinoline, for use as biochemical markers of collagen degradation. Clin. Chem. 42, 1621-1626 (1996). 

In both the ay and a2 chains of type I collagen, degradation of the protein begins with cleavage of the Gly-De or the Gly-Leu bond by collagenase. 

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