Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Cyst fluids from 55 premenopausal women with gross cystic breast disease were classified by K+/Na+ ratio: 19 with ratio over 1 (type I) and 36 with ratio less than 1 (type II). Immunoradiometric assay of cathepsin D in both types of cyst fluids revealed the presence of large amounts of this proteinase. The average concentration of cathepsin D in type I cyst fluids was 63.3 nmol/l, which was significantly higher than that corresponding to type II cyst fluids (35.1 nmol/l). Immunoprecipitation analysis of intracystic cathepsin D demonstrated that this protein was present as the 52 kD non-processed precursor form of the molecule. Since procathepsin D is a useful prognostic marker in breast carcinoma, we suggest that cyst fluid quantification of cathepsin D could aid to detect patients affecting of gross cystic disease with higher risk for developing breast cancer.
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PMID:Quantification and molecular analysis of cathepsin D in breast cyst fluids. 152 2

Antibody against purified bovine cathepsin D was raised in rabbits, and the polyclonal antiserum was tested to determine its ability to inhibit the hemoglobinolytic activity of the crude enzyme preparation (CEP) from adult Schistosoma japonicum and its effect upon in vitro cultured Schistosoma mansoni schistosomules. The 100,000 g supernatant fraction (CEP) from lyophilized adult worms was preincubated with antiserum and subsequently incubated with hemoglobin. Hemoglobinolytic activity was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoretic procedures. Five hours of incubation failed to diminish hemoglobin concentration in experimentals, whereas controls treated with preimmune serum displayed hemoglobin degradation. Pepstatin inhibited hemoglobin degradation. Western blot analysis of the CEP revealed a broad band of activity at approximately 45 kDa. Schistosomules incubated in vitro either in the antiserum or pepstatin and subsequently exposed to host erythrocytes showed a marked inhibition of digestive activities. Although structural changes were not evident in the gastrodermis, some perturbation of the tegument was observed. Schistosomules fed host erythrocytes and postincubated in the antiserum displayed increased tegumental perturbation and extensive alteration of the gastrodermis, including dilation of cisternae and membrane disruption. Schistosomules exposed to preimmune serum were normal in all respects.
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PMID:Schistosoma japonicum: immunoinhibitory studies on hemoglobin digestion using heterologous antiserum to bovine cathepsin D. 159 88

The effect of curing agents (salt, nitrate, ascorbic acid and glucose) and processing parameters (pH, water activity and drying and cooking temperatures) on pork muscle cathepsins B, D, H and L as well as leucyl, arginyl and tyrosyl hydrolysing activities is reported. Salt (60 g/l) showed a powerful inhibitory effect, especially on cathepsin D and aminopeptidase activities where less than 13% of the original activity was recovered. Cathepsin H was also affected (38% of the original activity) while cathepsins B and B+L recovered 72.5 and 63.0%, respectively. Nitrate (0.2-0.25 g/l) and ascorbic acid (0.2-0.4 g/l) did not significantly affect the enzyme activities. On the other hand, 0.5-2 g/l of glucose activated both cathepsins B and D with an increase of 39.5 and 28.5% and also leucyl and arginyl hydrolysing activities which were 75.0 and 24.0%, respectively. No aminopeptidase activity was detected when assayed in 100 mM sodium citrate buffer, pH 5.1. Cathepsin H was also very affected at that pH and only 12.0% of activity was recovered. A decrease in water activity, especially below 0.84, also affected the enzyme activities which were found below 50%. Temperatures in the usual range of the drying process (22 and 30 degrees C) gave substantial enzyme activities (around 40-50 and 80%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Activities of pork muscle proteases in model cured meat systems. 161 Sep 40

A novel renin inhibitor, YM-21095 [2RS), (3S)-3-[N alpha-[1,4-dioxo-4-morpholino-2-(1-naphthylmethyl)-buthyl]-L- histidil-amino]-4-cyclohexyl-1-[(1-methyl-5-tetrazolyl)thio]-2-but anol), has been synthesized in our laboratories. The aim of this study was to evaluate the pharmacological properties of YM-21095 in in vitro and in vivo experiments. YM-21095 inhibited human renin with an IC50 value of 4.7 x 10(-10) mol/L. YM-21095 was also a potent inhibitor against squirrel monkey renin, but less effective against renins from dog, rabbit, and rat. The effect of YM-21095 is highly specific for renin, since it did not inhibit cathepsin D, pepsin, or angiotensin converting enzyme up to a concentration of 10(-4) mol/L. YM-21095 was resistant to proteolytic actions of the enzymes (pepsin, chymotrypsin, trypsin) and squirrel monkey tissue homogenates (liver, kidney, small intestine). Intravenous infusion of YM-21095 (0.1 to 100 micrograms/kg/min) decreased mean blood pressure and inhibited plasma renin activity in a dose-dependent manner with no effect on heart rate in anesthetized sodium-depleted and sodium-replete squirrel monkeys. The hypotensive effect of YM-21095 in sodium-depleted squirrel monkeys was about ten times as potent as that in sodium-replete squirrel monkeys. Oral administration of YM-21095 to conscious sodium-depleted squirrel monkeys produced dose-related decreases of systolic blood pressure. We conclude that YM-21095 is a potent and highly specific inhibitor of primate renin and produces a blood pressure lowering effect.
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PMID:Pharmacological properties of YM-21095, a potent and highly specific renin inhibitor. 181 49

Action of purified human cathepsin B on recombinant single-chain urokinase-type plasminogen activator (pro-uPA) generated enzymatically active two-chain uPA (HMW-uPA), which was indistinguishable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot from plasmin-generated HMW-uPA and from elastase- or thrombin-generated inactive two-chain urokinase-type plasminogen activator. Preincubation of cathepsin B with E-64 (transepoxysuccinyl-L-leucylamino- (4-guanidino)butane, a potent inhibitor for cathepsin B) prior to the addition of pro-uPA prevented the activation of pro-uPA. The cleavage site within the cathepsin B-treated urokinase-type plasminogen activator (uPA) molecule, determined by N-terminal amino acid sequence analysis, is located between Lys158 and Ile159. Pro-uPA is cleaved by cathepsin B at the same peptide bond that is cleaved by plasmin or kallikrein. Binding of cathepsin B-activated pro-uPA to the uPA receptor on U937 cells did not differ from that of enzymatically inactive pro-uPA, indicating an intact receptor-binding region within the growth factor-like domain of the cathepsin B-treated uPA molecule. Not only soluble but also tumor cell receptor-bound pro-uPA could be efficiently cleaved by cathepsin B to generate enzymatically active two-chain uPA. Thus, cathepsin B can substitute for plasmin in the proteolytic activation of pro-uPA to enzymatically active HMW-uPA. In contrast, no significant activation of pro-uPA by cathepsin D was observed. As tumor cells may produce both pro-uPA and cathepsin B, implications for the activation of tumor cell-derived pro-uPA by cellular proteases may be considered.
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PMID:Cathepsin B efficiently activates the soluble and the tumor cell receptor-bound form of the proenzyme urokinase-type plasminogen activator (Pro-uPA). 190 May 15

The release of T4 and T3 from the prohormone thyroglobulin (Tg) occurs in thyroid lysosomes. To examine the role of cathepsin-B, -D, and -L, the three major endopeptidases in this process, we incubated rabbit [125I]Tg, labeled in vivo, with lysosomal extracts from human thyroids. Iodopeptide formation was evaluated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate after short term incubations (20-45 min), while iodoamino acid release was assessed by paper chromatography after long term incubations (8 and 24 h). Using pepstatin to inhibit cathepsin D, Z-Phe-Ala-CHN2 to inhibit both cathepsin B and L, and Z-Phe-Phe-CHN2 to selectively inhibit cathepsin L, we obtained the following results: 1) blocking of all three endopeptidases reduced both iodopeptide formation in short term experiments and iodoamino acid release in long term experiments by 80-90%; 2) iodopeptide formation was reduced by 85% with Z-Phe-Ala-CHN2, by 56% with Z-Phe-Phe-CHN2, and by 26% with pepstatin; 3) iodoamino acid release was reduced by 60-80% with Z-Phe-Ala-CHN2 and by 40-50% with either Z-Phe-Phe-CHN2 or pepstatin at 8 h, but by less than 20% at 24 h; pepstatin and Z-Phe-Phe-CHN2 together reduced iodoamino acid release by 80% and 60% at 8 and 24 h, respectively. Limited hydrolysis of Tg by lysosomal enzymes produced at least eight peptide fragments of less than 100,000 mol wt. Three of these, together representing 32% of the 125I released, resulted from cleavages in the C-terminal region of Tg corresponding to residues 2487, 2393, and 2390 of cDNA-derived human Tg. Several other peptides, together containing 38% of the 125I released, included the N-terminus of Tg. These C-terminal and N-terminal fragments contained three of Tg's four major hormonogenic sites, but none of the cleavage sites fell close to the hormone sites themselves. We conclude that 1) the formation of discrete iodopeptides precedes the release of iodothyronines and iodotyrosines from Tg; 2) the cysteine proteinases are more important than cathepsin D in this process; and 3) these endopeptidases selectively cleave Tg to favor the production of hormone-containing intermediates for subsequent processing by exopeptidases.
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PMID:Proteolytic processing of thyroglobulin by extracts of thyroid lysosomes. 190 99

The normal provision of thyroid hormones to the body requires their release from the prohormone, thyroglobulin (Tg). Previous work established the importance of cathepsins B, D, and L (formerly designated cysteine proteinase I) to this process but had not defined the points of proteolytic attack for each enzyme. In the present study we labeled rabbit Tg in vivo with sodium 125I and performed limited digestions with cathepsins B, D, and L, purified from human thyroids. The resultant peptide fragments were analyzed by amino-terminal sequencing and located within the Tg molecule by comparison with the cDNA-derived sequences from human Tg. We identified three cleavage points for cathepsin B, corresponding to P'1 residues 532, 795, and 2487; four cleavage points for cathepsin L, corresponding to P'1 residues 2389, 2452, 2490, and 2657; and four cleavage points for cathepsin D, corresponding to P'1 residues 551, 1835, 2468, and 2643. None of the cleavage points was near Tgs known hormonogenic sites, but these peptide fragments contained three of the four major hormonogenic sites in rabbit Tg, suggesting some preference for their early proteolytic processing. Cathespin B alone among the three endopeptidases had some exopeptidase activity toward Tg. The cleavage specificities for each of the endopeptidases resembled those described with other protein substrates. Thus, cathepsin D preferentially cleaved bonds between hydrophobic residues, and cathespin L cleaved bonds with hydrophobic residues at P2 and P3. Although cathepsin Bs specificity was less obvious, it produced a major cleavage between 2 leucine residues. The existence of three endopeptidases cleaving at different sites shows that Tg proteolysis is a complex process, suggests synergism among their enzyme activities, and provides a physiological mechanism for selective hormone release, including its regulation by TSH.
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PMID:Thyroglobulin processing by thyroidal proteases. Major sites of cleavage by cathepsins B, D, and L. 193 80

We recently reported that a subpopulation of immunoglobulin G (IgG) in man interacts with the hormone-binding site of estrogen receptors (ER), competes with [3H]estradiol (E2) uptake, and decreases effective ER concentrations in cell cultures. The present work further characterizes the immunological properties of these antibodies and defines their biological activity. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting techniques, enriched preparations of the natural anti-ER IgG subpopulation (IgGs) were found to specifically immunoprecipitate ER extracted from MCF-7 mammary carcinoma cells and to compete with [3H]tamoxifen-aziridine for ER binding. During 18-h incubations IgGs decreased [3H]E2 binding capacity of MCF-7 cells in a dose-dependent manner similar to E2. Like E2 but unlike antiestrogens, this biological effect corresponded to down-regulation of the receptor protein and depended on a mechanism specifically inhibited by actinomycin D. Moreover, IgGs antagonized the decrease of [3H]E2 binding capacity produced by the strong antiestrogen methyl-hydroxytamoxifen; this antagonism was additive to that of E2. On the other hand, IgGs like estrogens increased progesterone receptor concentrations and cathepsin D secretion. The biological activity of IgGs was neutralized by anti-IgG antibodies and by ICI 164,384, a "pure" steroid antagonist of E2, confirming that immunoglobulins G were responsible for this activity and acted at the E2-binding site. These observations indicate that some natural antibodies in man can function like potent estrogens on ER and mammary cells.
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PMID:Estrogen-like activity of a subpopulation of natural antiestrogen receptor autoantibodies in man. 203 91

The conformational changes of human apolipoprotein (apo) B-100 which accompany the conversion of plasma very low density lipoproteins (VLDL) to low density lipoproteins (LDL) were investigated by studying the accessibility of apoB-100 in LDL and VLDL to limited proteolysis with cathepsin D, an aspartyl proteinase involved in intracellular protein degradation. We characterized the proteolytic products of apoB-100 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by NH2-terminal sequence analysis to locate cleavage sites. The results identified at least 10 cleavage products generated from apoB-100 and showed differential accessibility of cleavage sites for cathepsin D in apoB-100 between LDL and VLDL. We identified a specific peptide region (residues 2660-2710), which is preferentially accessible to limited proteolysis by cathepsin D but inaccessible to limited proteolysis by 12 other enzymes tested. Within this peptide region, cathepsin D cleaved apoB-100 of LDL and VLDL preferentially at different sites, separated by 33-36 amino acids (2665-2666 or 2668-2669 (LDL) and 2701-2702 (VLDL]. In addition, we identified a cleavage site, located at residues 3272-3273, specific for cathepsin D, which is contained within the COOH-terminal enzyme-accessible peptide region (residues 3180-3280), which we have demonstrated using 12 endoproteases with various specificities. The previously identified NH2-terminal region (residues 1280-1320) appears to be resistant to limited cleavage by cathepsin D. However, a new site was revealed only approximately 66 kDA from the NH2 terminus. We conclude that differential accessibility and the shift of the novel scission site for cathepsin D by 33-36 amino acids indicate significant differences in local conformation at these sites in apoB-100 as VLDL are converted to LDL.
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PMID:Differences in local conformation in human apolipoprotein B-100 of plasma low density and very low density lipoproteins as identified by cathepsin D. 206 28

There are at least three stages in the targeting of soluble lysosomal enzymes: transfer of N-acetylglucosaminyl 1-phosphate to high-mannose oligosaccharide side chains, removal of N-acetylglucosamine and recognition of the "uncovered" mannose 6-phosphate residues. Defects in the transfer reaction cause mucolipidoses II and III. Those in the subsequent stages of the targeting may result in similar clinical disorders. To differentiate between possible defects of the targeting in cultured cells we have developed a procedure for a combined detection of the phosphorylation, uncovering of the transferred phosphate residues and the targeting of lysosomal enzymes. For this purpose cultured cells are metabolically labelled with [32P]phosphate and a lysosomal enzyme, such as cathepsin D, is isolated from the labelled cells and the medium by immunoprecipitation. The immunoprecipitates are dissolved with sodium dodecylsulphate and incubated in the presence and absence of calf intestine alkaline phosphatase. We show that the treatment of the denatured protein results in hydrolysis of phosphomonoester groups and that the phosphodiester and the peptide bonds remain intact. The initial and the residual radioactivity associated with the lysosomal enzyme which represent the total phosphate and the phosphodiester groups, respectively, are determined by gel-electrophoresis, fluorography and densitometry. This procedure extends one of the previously established methods for the diagnosis of mucolipidoses II and III.
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PMID:Determination of the phosphorylation, uncovering of mannose 6-phosphate groups and targeting of lysosomal enzymes. 207 12


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