Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to identify the specific proteoglycans and glycosaminoglycans (GAGs) in the leaflets and chordae of the mitral valve and to interpret their presence in relation to the tensile and compressive loads borne by these tissues. Leaflets and chordae from normal human mitral valves (n = 31, obtained at autopsy) were weighed and selected portions digested using proteinase K, hyaluronidase, and chondroitinases. After fluorescent derivatization, fluorophore-assisted carbohydrate electrophoresis was used to separate and quantify the derivatized saccharides specific for each GAG type. In addition, the lengths of the chondroitin/dermatan sulfate chains were determined. Proteoglycans were identified by western blotting. The regions of the valve that experience tension, such as the chordae and the central portion of the anterior leaflet, contained less water, less hyaluronan, and mainly iduronate and 4-sulfated N-acetylgalactosamine with chain lengths of 50-70 disaccharides. These GAGs are likely associated with the small proteoglycans decorin and biglycan, which were found in abundance in the tensile regions. The valve regions that experience compression, such as the posterior leaflet and the free edge of the anterior leaflet, contained significantly more water, hyaluronan, and glucuronate and 6-sulfated N-acetylgalactosamine with chain lengths of 80-90 disaccharides. These GAGs are likely components of water-binding versican aggregates, which were abundant in the compressive loading regions. The relative amounts and distributions of these GAGs are therefore consistent with the tensile and compressive loads that these tissues bear. Finally, the concentrations of total GAGs and many different chondroitin/dermatan sulfate subclasses were significantly decreased with advancing age.
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PMID:Glycosaminoglycans and proteoglycans in normal mitral valve leaflets and chordae: association with regions of tensile and compressive loading. 1504 91

During mammalian follicle development, a fluid-filled antrum develops in the avascular centre of the follicle. We investigated the hypothesis that follicular fluid contains osmotically-active molecules, sufficiently large so as to not freely escape the follicular fluid. Such molecules could generate an osmotic differential and thus recruit fluid from the surrounding vascularised stroma into the antrum. Follicular fluid was collected from bovine follicles classified histologically as healthy (n = 4 pools) or atretic (n = 4 pools). Dialysis of the follicular fluid at 300 kDa or 500 kDa resulted in a reduction in colloid osmotic pressure of 35% and 60%, respectively, in fluid from healthy follicles and 29% and 80% from atretic follicles. Digestion of follicular fluid with Streptomyces hyaluronidase, chondroitinase ABC or DNase 1 followed by dialysis resulted in reductions in osmotic pressure of 43%, 53% and 43% respectively for fluids from healthy follicles and 34%, 20% and 31% for atretic follicles. Digestion with collagenase I, proteinase K, heparanase 1 or keratanase had no significant effect on the osmotic pressure of follicular fluid of healthy follicles. Ion exchange and size exclusion, Western blotting and ELISA identified the proteoglycans versican and inter-alpha trypsin inhibitor and the glycosaminoglycan hyaluronan in follicular fluid. We conclude that these molecules or aggregates of them are of sufficient size to contribute to the osmotic potential of follicular fluid and thus recruit fluid into the follicular antrum. DNA may also contribute but it is probably not a component that is regulated for this role.
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PMID:Formation of ovarian follicular fluid may be due to the osmotic potential of large glycosaminoglycans and proteoglycans. 1681 38