Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pseudoxanthoma elasticum (PXE) is a heritable disorder of connective tissue that is characterized by redundant folds of skin in flexural areas. There is considerable evidence that suggests that the elastic fiber is the main site of the abnormality although the primary molecular defect has not been identified. The aim of this study was to identify differences between PXE and normal skin elastins. Elastins from normal, nonsolar-exposed skin, and pseudoxanthoma elasticum lesional skin were purified and their solubilization by pancreatic elastase was compared. Results demonstrated that elastin derived from normal skin was more susceptible to proteolytic cleavage than elastin purified from either pseudoxanthoma elasticum lesional skin or ligamentum nuchae. Pretreatment of the lesional elastin with testicular hyaluronidase increased its solubilization two-fold and generated a unique 15,000 Da molecular weight fragment. Elastin prepared from PXE skin may contain bound glycosaminoglycans which interfere with elastase activity. The susceptibility of normal skin elastin to proteolytic degradation may have implications in the study of aging skin.
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PMID:Elastase digestion of normal and pseudoxanthoma elasticum lesional skin elastins. 193 14

Skin biopsies from patients with pseudoxanthoma elasticum (PXE) were studied by electron microscopy either before or after selective digestions with collagenase, elastase, trypsin, hyaluronidase, chondroitinase AC and ABC, with the aim of identifying an eventual organic component associated with mineralization within the elastin fibers and the chemical nature of the enormous aggregates of filaments very often associated with, but distinct from mineralized elastin fibers. The results obtained, on both embedded thin sections and fresh tissue fragments, showed that elastin fibers, whether mineralized or not, were sensitive only to elastase, and they did not contain significant amounts of materials different from elastin that could be accounted for by ion precipitation; the aggregates of microfilaments in strict connection with altered elastin fibers were mostly sensitive to elastase and hyaluronidase, were partially removed by trypsin and chondroitinase, and were not modified by collagenase, which seems to indicate that the microfilaments consist mainly of abnormally aggregated elastin molecules together with low sulfated proteoglycans. It may be concluded that PXE is a complex genetic disorder of the connective tissue, and that mineralization of elastin is only one of the alterations of the extracellular matrix.
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PMID:Effect of selective enzymatic digestions on skin biopsies from pseudoxanthoma elasticum: an ultrastructural study. 301 57

Pseudoxanthoma elasticum is a genetic disease characterized by progressive mineralization of elastic fibers. Previous studies suggested that other components, apart from elastin, might be involved in the alterations of this connective tissue disorder (Martinez-Hernandez and Huffer, 1974; Pasquali Ronchetti et al., 1981; 1986). Evidence is presented that proteoglycan metabolism is altered in PXE-affected patient. Urinary GAGs suggests an increased degradation of glucosamine-containing GAGs in the patient. Pulse and chase experiments on in vitro skin fibroblasts indicated a decreased rate of synthesis of [35SO4] containing GAGs or an increase of their turnover rate in PXE. Moreover, when PGs produced from skin fibroblasts were identified by ultracentrifugation and gel filtration in associative conditions, PXE fibroblasts produced a significantly higher amount of the high molecular weight fraction of sulfated PGs. This high molecular weight material was present both in the medium and in the matrix and disappeared under dissociative conditions or after treatment with hyaluronidase or with pancreas elastase. By electron microscopy, PXE fibroblasts appeared to produce and secrete an enormous amount of toluidine blue 0 positive material organized as filaments and amorphous masses. These data are in agreement with previous observations of the presence of abnormal masses of microfilaments, in the dermis of PXE patients, which were sensitive to hyaluronidase and partially to trypsin and elastase (Pasquali Ronchetti et al., 1986). The results seem to confirm that at least some of the alterations of connective tissues in PXE are due to abnormal PGs metabolism and to their tendency to form abnormal aggregates in the extracellular space.
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PMID:Pseudoxanthoma elasticum (PXE): ultrastructural and biochemical study on proteoglycan and proteoglycan-associated material produced by skin fibroblasts in vitro. 334 48