Autoantibodies to basement membrane and interstitial collagens may participate in the pathogenesis of scleroderma.Decreased beta-isomerization of the C-terminal telopeptide of type I collagen alpha 1 chain in Paget's disease of bone.In Paget's disease of bone, the normal lamellar bone is replaced by a woven structure with an irregular arrangement of collagen fibers. In this study, we investigated whether the degree of beta-isomerization within C-telopeptide of alpha 1 chain of type I collagen was altered in Paget's disease compared with other bone diseases with no alteration of bone structure. In Paget's disease (n = 26), but not in patients with primary hyperparathyroidism (n = 6) or hyperthyroidism (n = 17), the urinary excretion of nonisomerized (alpha) fragments derived from degradation of type I collagen C-telopeptide (CTX) was markedly increased compared with beta-isomerized CTX (+ 13-fold vs. + 3-fold over controls) resulting in an urinary alpha CTX/beta CTX ratio 3-fold higher than in controls (2 +/- 1 vs. 0 +/- 0, p < 001). In five pagetic patients in complete remission, as demonstrated by normal total alkaline phosphatase activity, the alpha CTX/beta CTX ratio was normal. The immunohistochemistry of normal and pagetic human bone sections showed a preferential distribution of alpha CTX within woven structure, while lamellar bone was intensely stained with an anti-beta CTX antibody, suggesting a lower degree of beta-isomerization of type I collagen in the woven pagetic bone. In collagenase digest of human bone specimens, we found a lower proportion of beta-isomerized type I collagen molecules in pagetic bone (40% of beta CTX) than in normal bone taken from trabecular (68%) and cortical compartments (71%). In conclusion, we found that in Paget's disease the alpha CTX/beta CTX ratio in bone and in urine is markedly increased. squalane cleanser altered beta isomerization can be accurately detected in vivo by measuring urinary degradation products arising Collagen degradation within subcutaneous air pouches in vivo: the effects of A straightforward in vivo model of collagen degradation is described that can be used to measure the effects of different classes of proteinase inhibitors. Air pouches, formed subcutaneously in the dorsal thoracic region of rats, were inflamed 6 to 8 days later by injecting lambda-type carrageenan. 14C-Collagen was injected into the air pouches either 1 day before or 1 day after lambda-carrageenan-induced inflammation: in the latter case, the inflammatory exudate fluid was drained from the air pouches immediately prior to administering 14C-collagen. Ninety percent of the 14C-collagen was degraded and cleared within 3 days from pre-inflamed air pouches, but degradation was much slower from the post-inflamed or non-inflamed air pouches. Proteinase inhibitors injected simultaneously with the 14C-collagen, and again 6 hr later, reduced the extent of 14C-collagen degradation from air pouches measured after 24 hr. Forty-two percent of the degradation of 14C-collagen could be inhibited by a mixture of enzyme inhibitors (leupeptin, alpha 1-anti-proteinase, aprotinin, and pepstatin) injected together with 1,10 phenanthroline, the zinc metalloenzyme inhibitor. The 1,10 phenanthroline alone caused a 33% inhibition of 14C-collagen degradation, and the inhibitor mixture given alone inhibited 14C-collagen loss by 25%. Approximately 60% of the degradation of 14C-collagen in this model was mediated by mechanisms resistant to this combination of proteinase inhibitors, which may indicate the significant involvement of non-enzymic modalities, or degradation in intracellular compartments inaccessible to extracellular agents.Relation of ionizing groups to the structure of the collagen fibril. Green biomanufacturing in recombinant collagen biosynthesis: trends and selection in various expression systems.Engineering, Northwest University, Xi'an 710069, Shaanxi, China. Chemical Engineering, Northwest University, Xi'an 710069, Shaanxi, China.Collagen, classically derived from animal tissue, is an all-important protein material widely used in biomedical materials, cosmetics, fodder, food, etc. squalene of recombinant collagen through different biological expression systems using bioengineering techniques has attracted significant interest in consideration of increasing market demand and the process complexity of extraction. Green biomanufacturing of recombinant collagen has become one of the focus topics. While the bioproduction of recombinant collagens (type I, II, III, etc. ) has been commercialized in recent years, the biosynthesis of recombinant collagen is extremely challenging due to protein immunogenicity, yield, degradation, and other issues. The rapid development of synthetic biology allows us to perform a heterologous expression of proteins in diverse expression systems, thus optimizing the production and bioactivities of recombinant collagen. This review describes the research progress in the bioproduction of recombinant collagen over the past two decades, focusing on different expression systems (prokaryotic organisms, yeasts, plants, insects, mammalian and human cells, etc.).
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