Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Extracellular cathepsin D has been observed by various cytochemical methods at sites of tissue injury. However, the role of this enzyme in connective tissue matrix degradation is uncertain because there are no histochemical methods for determining whether or not the cathepsin D is active at such sites in living tissues. We considered that the combined use of a labelled tight-binding inhibitor with immunoprecipitation of the enzymes might overcome this problem. We have explored the application of derivatives of the inhibitor pepstatin, as only active cathepsin D binds pepstatin tightly. A series of N-pepstatinyl-N'-dinitrophenyl-alpha, omega-diaminoalkanes were synthesized with alkyl-chain lengths of two, four and six carbon atoms. These compounds were tight-binding inhibitors of human cathepsin D. In fluorescence-quenching titrations the dinitrophenyl groups were also fully available to bind high-affinity anti-dinitrophenyl antibody. It was shown by immunodiffusion in gels and by gel permeation chromatography that N-pepstatinyl-N'-dinitrophenyl-1,6-diaminohexane was a bifunction inhibitor able to bind cathepsin D and anti-dinitrophenyl antibody at the same time.
Biochem J 1980 Dec 01
PMID:Interaction of dinitrophenyl-pepstatins with human cathepsin D and with anti-dinitrophenyl antibody. Development of potential reagents for the localization in vivo of active proteinases at sites of tissue injury. 679 37

In human fibroblasts, the recognition of lysosomal enzymes by cell surface receptors is mediated by mannose 6-phosphate residues located on oligosaccharides that can be cleaved by endo-beta-N-acetylglucosaminidase H. About half of these oligosaccharides, as isolated from beta-hexosaminidase and cathepsin D secreted by human skin fibroblasts, are anionic. Most of these are resistant to alkaline phosphatase. The resistance is due to alpha-N-acetylglucosamine residues linked to mannose 6-phosphate by a phosphodiester bond. The major phosphorylated oligosaccharides contain one and two and possibly three phosphate groups blocked by N-acetylglucosamine. Besides the blocked phosphate groups these oligosaccharides contain a common inner core consisting of Man alpha 1,6-(Man alpha 1,3)Man alpha 1,6(Man alpha 1,3)Man beta GlcNAc and either one or two alpha 1,2-linked mannose residues.
Proc Natl Acad Sci U S A 1980 Dec
PMID:Phosphorylated oligosaccharides in lysosomal enzymes: identification of alpha-N-acetylglucosamine(1)phospho(6)mannose diester groups. 693 53

The kininogenase activity of highly purified preparations of cathepsins D from human liver and spleen, leukemic infiltrate obtained from patients with myeloic leukemia, and from chicken liver was studied. It was found that pepstatin, a specific inhibitor of carboxylic proteinases, inhibits this activity of cathepsins D. Interaction of chicken liver cathepsin D with human plasma substrate, which is possibly a low molecular weight kininogen (Ks = 1.3.10(-7) M) results in a production of the bradikinin analog methionyl-lysyl-bradikinin. The role of cathepsins D as potent inflammatory agents responsible for the generation of biologically active peptides--mediators of inflammation from the protein substrates including kininogens under desintegration of lysosomes is discussed.
Biokhimiia 1980 Dec
PMID:[Kininogenase activity of cathepsins D]. 694 16

The ultrastructural cytochemical reactivity, renin activity, and cathepsin D activity of atria and ventricle of the bullfrog have been assessed. The specific granules (A, B, and D) were found to be argentaphobic when ultrathin sections of Araldite-embedded atria and ventricle were stained according to the periodic acid-thiocarbohydrazide-silver proteinate technique of Thiery. The entire core of the specific granules was moderated positive after ultrathin sections of glutaraldehyde-fixed, glycol methacrylate embedded atria and ventricle were stained by phosphotungstic acid at a low pH. A similar reaction was shown by the cell coat, intercalated discs, residual bodies (C granules), and Z discs as well as by a very small portion of the Golgi complex. Incubation of ultrathin sections of atria and ventricule fixed only in glutaraldehyde and embedded in glycol methacrylate with either pronase or trypsin resulted in selective digestion of specific granules and Z discs and, to a much lesser degree, of the cell coat. As cathepsin D activity and renin activity were present in both atria and ventricle, the generation of angiotensin I by these cardiocytes might have been due to either enzyme. Nevertheless, because of the glycoprotein nature of specific granules and of the endocrinelike ultrastructure of atrial and ventricular cardiocytes in the frog, the present results raise the possibility that specific granules may contain renin.
Can J Physiol Pharmacol 1980 Dec
PMID:Ultrastructural cytochemistry of atrial and ventricular cardiocytes of the bullfrog (Rana catesbeiana). Relationship of specific granules with reninlike activity of the myocardium. 701 73

Activities and subcellular distributions of acid hydrolases, cathepsin D, acid phosphatase and beta-glucuronidase in myocardial subfractions were determined serially with reference to the initiation of myocardial necrosis in dog hearts with acute ischemia. The following results were obtained: 1) In the normal myocardium, respectable activities of three enzymes were obtained either in the sarcoplasmic reticulum or in the lysosome-containing fraction. 2) Thirty min after coronary ligation, an increase in the activities was observed in both lysosome and sarcoplasmic reticulum fractions of the ischemic heart muscle. After 60 to 90 min these activities were decreased rapidly in both fractions to about 70% of those of the normal myocardium with an increase in the cytosolic activity. Two to 3 hours after ligation, the reduction in the cytosolic activity was noted, indicating an escape of the enzymes from the necrotic myocardium. The subcellular distribution of these enzymes was further altered in the ischemic heart muscle for 12 to 14 hours reflecting an infiltration of the interstitial cells. These findings suggest that activation and release of acid hydrolases not only in lysosomes but also in the sarcoplasmic reticulum are one of the primary and the earliest factors for the evolution of ischemic myocardial injury which leads to necrosis.
Jpn Circ J 1982 Dec
PMID:Studies on intracardiac acid hydrolases in the ischemic myocardial necrosis. 714 2

Pepstatin, a specific inhibitor of pepsin, cathepsin D (E), renin, etc., was used in a new method to demonstrate the sites of enzymes. Pepstatin (Pst) was covalently attached to glutathione (GSH), using a dicyclohexylcarbodiimide, and CH3Hg+ was then put in the residue of SH for electron microscopic observation. Pst-GS-HgCH3 thus obtained was nonisotopical, had a very low molecular weight (about 1,200 daltons), and still almost completely retained its inhibitory activity. Sections of rat liver (less than 1 mm3 thick), prefixed by glutaraldehyde, were incubated in the prepared reaction medium. Cathepsin D, located in the lysosomes, was demonstrated by this compound, but when the sections were preincubated with pepstatin, this was not the case. These results demonstrate that mercury-labeled pepstatin is a useful reagent for the histochemical staining of acid proteases for electron microscope.
J Histochem Cytochem 1982 Dec
PMID:Electron microscopic visualization of cathepsin D using mercury-labeled pepstatin as an enzyme inhibitor. 715

Cathepsin D (EC 3.4.23.4) was purified from rabbit skeletal muscle using acetone-dried muscle powder as starting material. After the acetone-dried powder was extracted with 0.2 mM ATP, the extract was fractionated with acetone an subjected to DEAE-Sephadex A-50 and Sephadex G-100 column chromatography. Rechromatography on a Sephadex G-100 column resulted in a purified preparation. SDS-polyacrylamide gel electrophoresis of the purified enzyme showed one major band of 42,000 daltons and some bands of contaminants. Since gel filtration also indicated a value of 42,000 daltons for the enzyme, it was concluded that muscle cathepsin D has no subunit structure. The enzyme acted optimally towards myofibrils around pH3, resulting in the degradation of the myosin heavy chain and production of a 30,000-dalton component.
Biochim Biophys Acta 1981 Dec 15
PMID:Purification of cathepsin D from rabbit skeletal muscle and its action towards myofibrils. 731 36

1. Pepstatinyl-cystamine was synthesized. The disulphide bond was cleaved and the pepstatin-bound thiol was made to react with monobromobimane. The fluorescent N-pepstatinyl-S-bimanyl-2-aminoethanethiol was purified. 2. Human cathepsin D showed tight binding of the bimane-labelled pepstatin at pH 3.5. The titration curves were used to determine the apparent dissociation constant, KD; values of approx. 1 x 10(-10) M were obtained. 3. Gel-chromatographic experiments showed that, like that of pepstatin, the binding of N-pepstatinyl-S-bimanyl-1-aminoethanethiol to cathepsin D was strongly pH-dependent. Binding was seen at pH 5.0, but could not be demonstrated at pH 7.4. 4. Cultured human synovial cells were fixed and incubated with the fluorescent inhibitor at pH 5.0 or pH 7.4. When examined by fluorescence microscopy the cells stained at pH 5.0 showed a punctate perinuclear distribution of bimane fluorescence. By contrast, the cells stained at pH 7.4 showed no fluorescence. 5. The distribution of cathepsin D, determined by indirect immunofluorescence at pH 7.4, closely resembled that of the fluorescent inhibitor seen at pH 5.0. 6. We conclude that N-pepstatinyl-S-bimanyl-2-aminoethanethiol is a fluorescent probe selective for the active conformation of cathepsin D.
Biochem J 1981 Dec 01
PMID:Bimane-labelled pepstatin, a fluorescent probe for the subcellular location of cathepsin D. 734 Aug 22

Pulmonary alveolar macrophages (PAM) were harvested from conventional (CONV), germfree (GF), conventionalized, and monoassociated (MA) rats. Germfree rats had significantly fewer PAM than did their CONV, conventionalized or MA counterparts. The bronchopulmonary wash from the CONV and conventionalized rats contained higher lysosomal specific activity for beta-glucuronidase and cathepsin D than did similar washes from GF rats. Cellular and subcellular PAM fractions from GF rats also showed decreased enzyme activity in comparison with similar fractions from the PAM or CONV rats. Colonization of GF rats with one (MA) or more bacterial species (conventionalized) increased the beta-glucuronidase and cathepsin D activity of their PAM as well as total PAM. These data suggest that the intestinal flora not only enhances PAM proliferation but also is associated with an increase in their lysosomal enzyme activity.
J Reticuloendothel Soc 1981 Dec
PMID:Lysosomal enzyme activity in pulmonary alveolar macrophages from conventional, germfree, monoassociated, and conventionalized rats. 734 72

Approximately 20% of the radioactivity incorporated into the dentine collagen of unerupted bovine molars after reduction with tritiated sodium borohydride was recovered in a cyanogen bromide peptide fraction of Mr 61 000 following chromatography on agarose A5m. After rechromatography on agarose A1.5m, this fraction was resolved into ten components by gel isoelectric focusing. Of these components, nine (the most acidic) were tritiated and contained the reduced cross-links dihydroxylysinonorleucine and hydroxylysinonorleucine. The amino acid compositions were consistent with the identification of each of these components as alpha 2CB3,5 linked to one or two small peptides. By limited Edman degradation, with and without prior digestion with pyroglutamate aminopeptidase (EC 3.4.11.8), these small peptides were identified as alpha 1CB0,1 and alpha 2CB1, occurring in a ratio of approximately 2:1. Specific cleavage with cathepsin D revealed that all the cross-link was associated with the C-terminal one-third of the alpha 2 chain, thus fixing the displacement of the participating molecules at 4D. The content of the known reducible cross-links present in these peptides, calculated from the specific activity of the reductant, was sufficient to account for only 10--20% of the cross-linking actually found, suggesting that stabilization is mainly through nonreducible cross-links of as yet undetermined structure. By quantitative analysis of homoserine content and semiquantitative amino-terminal analyses, it was determined that virtually all of the alpha 2 chain of bovine dentine collagen is cross-linked in this manner. One cross-link per molecule in this location could made a major contribution to the mechanical stability of the insoluble collagen fibrils in this tissue.
Biochemistry 1980 Dec 23
PMID:A major intermolecular cross-linking site in bovine dentine collagen involving the alpha 2 chain and stabilizing the 4D overlap. 747 Apr 54


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