title: Detection of remnant proteolytic activities in unimplanted glutaraldehyde-treated bovine pericardium and explanted cardiac bioprostheses.
abstract: The presence and activity of proteolytic enzymes has been investigated in vitro on soluble and insoluble preparations obtained from both unimplanted and implanted glutaraldehyde-treated bovine parietal pericardium. Using detection by colorimetric techniques, soluble preparations were shown to hydrolyze enzyme substrates that are characteristic for trypsin-like proteases, cathepsin-like proteases, and collagenase. As detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in gradient gels and gel filtration on Sepharose CL-6B, insoluble (pellet) preparations degraded denatured type I collagen in a time-dependent pattern, producing low-molecular-weight fragments. These activities were partially inhibited by phenylmethylsulfonyl fluoride, N-ethyl maleimide, soybean trypsin inhibitor, para-chloromercuribenzoic acid, or ethylenediaminetetraacetic acid, suggesting the presence of a heterogeneous enzymatic mixture. Insoluble preparations incubated with pure pericardial dermatan sulfate proteoglycan detached the glycosaminoglycan chains from their core protein carrier, producing a digestion pattern similar to Cathepsin C. These findings demonstrate the presence of active proteases in glutaraldehyde-fixed bovine pericardium per se and in explanted pericardial bioprosthetic cardiac valves, an additional factor that might contribute to intrinsic extracellular matrix degeneration in pericardial bioprosthetic devices.
authors.affiliation: Cardiovascular Surgery Research Department, Public Health and Medical Research Institute, Tirgu Mures, Romania.
authors.forename: D
authors.initials: D
authors.lastname: Simionescu
authors.forename: A
authors.initials: A
authors.lastname: Simionescu
authors.forename: R
authors.initials: R
authors.lastname: Deac
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001705:Bioprosthesis; D002417:Cattle; D002850:Chromatography, Gel; D003094:Collagen / Q000378:metabolism; D003124:Colorimetry; D004591:Electrophoresis, Polyacrylamide Gel; D005976:Glutaral / Q000494:pharmacology*; D006350:Heart Valve Prosthesis; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000032:analysis*; D010496:Pericardium / Q000187:drug effects / Q000201:enzymology*; D011480:Protease Inhibitors / Q000494:pharmacology; D011509:Proteoglycans / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D011480:Protease Inhibitors; D011509:Proteoglycans; D012709:Serum Albumin; D003094:Collagen; D010447:Peptide Hydrolases; D005976:Glutaral