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

The kinin-forming enzyme of rat brain was studied by bioassaying kinin using a rat uterus. The enzyme released a kinin from the partially purified kininogen of rat plasma. The activity is exclusively distributed in the mitochondrial fraction and was detected in the pH range of 2.5-4.0 (optimally at pH 3.0). The enzyme was potently inhibited by pepstatin, but not by aprotinin. Released kinin was extracted by n-butanol and it was purified using Amberlite CG-50 absorption and CM-cellulose column chromatography. The elution profile of kinin from the CM-cellulose column did not coincide with that of bradykinin, Lys-bradykinin or Met-Lys-bradykinin. Isolated kinin was inactivated by treatment with chymotrypsin, but not with trypsin. In addition to the contractile activity on rat uterus, the kinin caused contraction of guinea pig ileum, with the response being potentiated by the presence of bradykinin-potentiator B. It also relaxed a rat duodenum, decreased rat blood pressure, and increased the vascular permeability in guinea pigs. Relative potencies of kinin on these pharmacological activities did not coincide with those of bradykinin. From these results, it is concluded that a kinin-forming enzyme is present in the rat brain. It is a cathepsin D-like enzyme, and furthermore, the enzyme releases a kinin-like peptide from the plasma kininogen fraction.
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PMID:Kinin-forming enzyme in rat brain mitochondria fraction and biological activity of a kinin released from rat plasma kininogen by this enzyme. 674 70

Lysosomal enzymes can, under certain circumstances, be secreted in large amounts. One example is uteroferrin (Uf), an iron-containing, purple-colored acid phosphatase secreted by the uterus of the pig during pregnancy. Uf is identical to the intracellular tartrate-resistant acid phosphatase of pig spleen, yet is the major protein component of uterine secretions. To investigate possible regulatory mechanisms that might direct Uf along a secretory pathway, we expressed Uf in Chinese hamster ovary (CHO) cells under the control of the SV40 early promoter using an expression construct, pX/Uf. The proportion of Uf secreted into the medium relative to the amount retained intracellularly increased as total Uf expression was increased. At transfection doses of 15 micrograms pX/Uf per 10(6) cells, over 80% of the Uf produced in 48 h was secreted. A parallel situation was observed when human cathepsin D was overexpressed in CHO cells. Thus, high production of Uf, as occurs in the uterus in response to progesterone, may overwhelm the intracellular enzymatic and receptor systems that are normally employed to target acid hydrolases to lysosomes, resulting in secretion. Both Uf and cathepsin D secreted by CHO cells possess N-linked, phosphorylated high-mannose oligosaccharide chains. However, the phosphate groups on the oligosaccharide chains of Uf, unlike those on cathepsin D, cannot be readily removed by alkaline phosphatase treatment. These results suggest that the phosphate groups on Uf are masked at least partially by covering N-acetylglucosamine residues and that two mechanisms may contribute to hypersecretion of Uf in the uterus: 1) very high rates of synthesis and 2) partial masking of the mannose 6-phosphate recognition signal.
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PMID:Overexpression of uteroferrin, a lysosomal acid phosphatase found in porcine uterine secretions, results in its high rate of secretion from transfected fibroblasts. 828 14

The lipid-rich residual bodies (LRRB) (Eyden et al., 1991) in human myometrium and uterine leiomyoma cells, have a distinctive ultrastructure characterised by a rich lipid content. To evaluate the biological or pathological significance in detail, normal myometrium and uterine leiomyoma from 30 human cases were studied by conventional histological, histochemical, immunohistochemical and electron microscopic methods. The study included a quantitative analysis of LRRBs of 3 premenarchic cases, 19 cases having a menstrual cycle, and 8 cases in menopause, in addition to 20 patients with histologically conventional leiomyoma larger than 3 cm in diameter. The study revealed the following findings: 1) immunohistochemical distribution of cathepsin D in the LRRB; 2) histochemical demonstration of neutral fat as the main content of LRRB; 3) statistically significant decrease in the distribution of LRRB in leiomyoma tissue compared with normal myometrium; 4) an absence or minimal distribution of LRRB in premenarchic myometrium; 5) a moderately significant correlation between the frequency of LRRB and patient's age. The distribution of cathepsin D within LRRB and the differential expression of LRRBs in the various smooth muscle cell tissues of the uterus suggest a possible role of ovarian hormones in the genesis of LRRBs which may function in the intra-lysosomal degradation of organelles produced during hormonal cycling.
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PMID:Lipid-rich residual bodies and cathepsin D in the human uterus: ultrastructural and quantitative comparison between normal myometrium and leiomyoma. 840 43

An acid proteinase of Dirofilaria immitis worms was purified 437-fold by gel filtration on Sephadex G-75 followed by pepstatin-Agarose gel affinity chromatography. The enzyme with a molecular weight of 42 kDa was homogeneous as judged by both affinity chromatography and SDS-polyacrylamide gel electrophoresis. Polyacrylamide disc electrophoresis at pH 8.9, however, revealed that the enzyme was composed of five multi-forms, all carrying proteinase activity. Optimum pH of the enzyme was in the range of pH 2.8 to 3.4, and its isoelectric point ranged between 5.8 and 6.4. The purified proteinase showed a potent activity against hemoglobin and myoglobin releasing acid soluble peptides, but not free amino acids. When enzymatic properties of the proteinase was compared with mammalian cathepsin D and pepsin, D. immitis proteinase activity was reduced to about 80% of the initial activity by incubating at neutral pH and 50 degrees C for 5 min, just like cathepsin D, which remained intact. Pepsin activity was completely destroyed under the same condition. An aspartic proteinase inhibitor, 1,2-epoxy-3-(p-nitrophenoxy)propane, which inhibited pepsin by 30% at 37 degrees C for 10 min, did show little effects on D. immitis proteinase and cathepsin D. Inhibitory effect of diazoacetyl-DL-norleucine methyl ester (DAN) on D. immitis proteinase was intermediate (50% after 60 min). Immunolocalization of the proteinase in the worm tissue using its monoclonal antibodies revealed that the enzyme was localized in the intestine as well as uterine wall and some small granules of microfilariae in the uterus.
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PMID:Purification and characterization of an acid proteinase from Dirofilaria immitis worms. 854 Mar 32

Overexpression of cathepsin D in several types of carcinoma in women appears to be associated with a poor clinical course. In this prospective investigation, cathepsin D levels in 170 specimens of normal and neoplastic human tissues were determined simultaneously by enzyme immunoassay (EIA) and immunoradiometric assay (IRMA) to allow comparisons in multicentric studies, such as cooperative clinical trials. Nonmalignant uteri and specially prepared reference powders were also evaluated. Linear regression analysis between the two assays for all specimens [EIA = 0.87(IRMA)-3.18] demonstrated a correlation coefficient (r) of 0.99 (P < 0.001). When malignancies were categorized by the tissue origin (i.e., breast, uterus, ovary, lymph node, and colon), highly significant correlations were also observed (regressions slopes ranged from 0.58 to 1.02). Intra- and interassay controls conducted for the new EIA procedure gave CV% ranging from 4.4 to 10.2, which was similar to the IRMA test for cathepsin D. The results of both assays correlated well and were highly reproducible. Either assay may be used with confidence that comparable cathepsin D values will be obtained in a wide range of tissue biopsies.
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PMID:Comparison of cathepsin D determinations in human carcinomas by enzyme immunoassay and immunoradiometric assay. 858 2

The estrogenic activity of dieldrin, toxaphene, and an equimolar mixture of both compounds (dieldrin/toxaphene) was investigated in the 21-day-old B6C3F1 mouse uterus, MCF-7 human breast cancer cells, and in yeast-based reporter gene assays. Treatment of the animals with 17beta-estradiol (E2) (0.0053 kg/day x3) resulted in a 3.1-, 4.8-, and 7.8-fold increase in uterine wet weight, peroxidase activity, and progesterone receptor binding, respectively. In contrast, treatment with 2.5, 15 and 60 micromol/kg (x3) doses of toxaphene, dieldrin, or dieldrin/toxaphene (equimolar) did not significantly induce a dose-dependent increase in any of the E2-induced responses. The organochlorine pesticides alone and the binary mixture did not bind to the mouse uterine estrogen receptor (ER) in a competitive binding assay using [3H]E2 as the radioligand. In parallel studies, estrogenic activities were determined in MCF-7 cells by using a cell proliferation assay and by determining induction of chloramphenicol acetyl transferase (CAT) activity in MCF-7 cells transiently transfected with plasmids containing estrogen-responsive 5'-promoter regions from the rat creatine kinase B and human cathepsin D genes. E2 caused a 24-fold increase in CAT activity in MCF-7 cells transiently transfected with creatine kinase B and a 3.8-fold increase in cells transiently transfected with the human cathepsin D construct. Treatment of MCF-7 cells with dieldrin, toxaphene, or an equimolar mixture of dieldrin plus toxaphene (10(-8)-10(-5) M) did not significantly induce cell proliferation or CAT activity in the transient transfection experiment with both plasmids. The relative competitive binding of the organochlorine pesticides was determined by incubating MCF-7 cells with 10(-9) M [3H]E2 in the presence or absence of 2 x 10(-7) M unlabeled E2 (to determine nonspecific binding), toxaphene (10(-5) M), dieldrin (10(-5) M), and equimolar concentrations of the dieldrin plus toxaphene mixture (10(-5) M). The binding observed for [3H]E2 in the whole cell extracts was displaced by unlabeled E2, whereas the organochlorine pesticides and binary mixture exhibited minimal to nondetectable competitive binding activity. E2 caused a 5000-fold induction of beta-galactosidase (beta-gal) activity in yeast transformed with the human ER and a double estrogen responsive element upstream of the beta-gal reporter gene. Treatment with 10(-6)-10(-4) M chlordane, dieldrin, toxaphene, or an equimolar mixture of dieldrin/toxaphene did not induce activity, whereas 10(-4) M endosulfan caused a 2000-fold increase in beta-gal activity. Diethylstilbestrol caused a 20-fold increase in activity in yeast transformed with the mouse ER and a single estrogen responsive element upstream of the beta-gal reporter gene. Dieldrin, chlordane, toxaphene, and endosulfan induced a 1.5- to 4-fold increase in activity at a concentration of 2.5 x 10(-5) M. Synergistic transactivation was not observed for any equimolar binary mixture of the pesticides at concentrations of either 2.5 x 10(-5) M or 2.5 x 10(-4) M. The results of this study demonstrate that for several estrogen-responsive assays in the mouse uterus, MCF-7 human breast cancer cells, and yeast-based reporter gene assays, the activities of both dieldrin and toxaphene were minimal, and no synergistic interactions were observed with a binary mixture of the two compounds.
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PMID:Estrogenic activity of a dieldrin/toxaphene mixture in the mouse uterus, MCF-7 human breast cancer cells, and yeast-based estrogen receptor assays: no apparent synergism. 907 11

An acidic proteinase was purified from human kidney cortex. The enzyme showed a molecular mass of 31 kDa by SDS-PAGE, 36 kDa by gel filtration, and isoelectric points of 5.2 and 6.1. The optimum pH for hydrolysis of bovine hemoglobin was about 3.5. Reverse-phase HPLC analysis of the incubation mixture of the enzyme with human plasma showed the presence of an active peptide on rat uterus muscle with the same retention time as the methionyl-lysyl-bradykinin (MLBK) standard. The specific activities were 2.91 micrograms MLBK equivalent mg-1.min-1 at pH 3.5 and 2.15 micrograms MLBK equivalent mg-1.min-1 at pH 6.0. All the enzymatic activities of this human kidney proteinase were inhibited by pepstatin A. Intramolecularly quenched fluorogenic substrates with amino acid sequences of human kininogen were used to determine the cleavage points. On the N-terminal sequences (Abz-Leu-Met-Lys-Arg-Pro-Eddnp and Abz-Met-Ile-Ser-Leu-Met-Lys-Arg-Pro-Eddnp) the cleavage occurred at the Leu-Met linkage, and on the C-terminal sequences (Abz-Phe-Arg-Ser-Ser-Arg-Eddnp and Abz-Phe-Arg-Ser-Ser-Arg-Gln-Eddnp) the cleavage occurred at the Arg-Ser linkage. Abz-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg-Ser-Ser-Arg-Gln-Eddnp++ + was hydrolyzed by the renal acidic proteinase and yielded the peptide Abz-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg (Abz-bradykinin). Kinectic parameters were determined using Abz-Met-Ile-Ser-Leu-Met-Lys-Arg-Pro-Eddnp (K(m) = 0.69 +/- 0.08 microM; Kcat = 0.052 +/- 0.0095 s-1; Kcat/K(m) = 0.075 +/- 0.005 microM-1.s-1) and Abz-Phe-Arg-Ser-Ser-Arg-Gln-Eddnp (K(m) = 1.56 +/- 0.16 microM; Kcat = 0.0048 +/- 0.0001 s-1; Kcat/K(m) = 0.003 +/- 0.0003 microM-1.s-1). Human liver cathepsin D had no activity on C-terminal sequences and human pepsin hydrolyzed them at the Ser-Ser bond. The results suggest that the renal acid proteinase is distinct from human pepsin and human liver cathepsin D and releases MLBK from human kininogen.
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PMID:Characterization of kininogenase activity of an acidic proteinase isolated from human kidney. 927 60

Proteolytic destruction of basement membrane and tumor surrounding is a prerequisite of invasion and metastasis. In 587 frozen samples of malignant and nonmalignant tissue of breast, uterus, vulva, and ovary, levels of urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) were examined with enzyme-linked immunosorbent assay (ELISA) and cathepsin D (cath D) with radioimmunoassay. UPA, PAI-1 and cath D were raised in malignant tissue with significantly higher levels in breast cancer (uPA, PAI-1) and ovarian cancer (cath D). TPA levels were lower in malignant tissue. In 393 primary breast cancer samples, uPA, PAI-1, and cath D were not related to other prognostic factors, whereas tPA levels were significantly raised in prognostic more favorable carcinomas. Over a follow-up period up to 46 months (median 30 months) the log-rank test showed in the whole group of breast cancer patients a significantly higher rate of relapse (p < 0.05) and death (p < 0.001) with tPA levels < 2.5 ng/mg. PAI-1 levels > 3 ng/mg were associated with shorter overall (p < 0.02; p = 0.01), disease-free (p < 0.008; p < 0.01), and metastasis-free (p < 0.04; p = 0.005) survival in all patients and in the node-negative subgroup, respectively. Higher uPA and cath D levels were not associated with rate of relapse or death over this follow-up period. The prognostic value of tumor-associated proteases could be of interest also in ovarian and cervical cancer.
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PMID:Protease levels in breast, ovary, and other gynecological tumor tissues: prognostic importance in breast cancer. 930 48

Previous studies have shown that acute, oral administration of malathion modulated the humoral immune response to T cell-dependent antigen, mitogenic responses, macrophage function and mast cell degranulation. In this report, the effects of malathion administration for 90 days on macrophage function, as measured by respiratory burst capacity, phagocytic capability and the production of cathepsin D, and mast cell integrity were assessed. A dose-dependent increase in respiratory burst activity was observed at all doses tested. The production of cathepsin D was elevated at doses of 1 mg/kg/day malathion or greater. The phagocytic capability of peritoneal macrophages was elevated at the dose of 0.1 mg/kg/day, but was suppressed at higher doses. The effect of oral administration of malathion for 90 days on the degranulation of mast cells, in both organs (skin and uterus) and peritoneal lavage fluid, was also assessed. Degranulation (both severe and slight) of mast cells from the skin and peritoneum was observed at a dose of 1.0 mg/kg/day or greater. In addition, the percentage of mast cells that were undegranulated was decreased. In the skin, but not the peritoneum, these effects were dose-dependent. In the uterus, the percentage of mast cells that were undegranulated was decreased and severely degranulated was increased at a dose of 0.1 mg/kg/day or greater. These data indicate that repeated administration of malathion increased macrophage function and led to mast cell degranulation at doses as low as 0.1 mg/kg/day for 90 days.
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PMID:Effect of administration of malathion for 90 days on macrophage function and mast cell degranulation. 938 85

3,3',4,4'-Tetrachlorobiphenyl (tetraCB) binds to the aryl hydrocarbon receptor (AhR), and several reports have demonstrated that AhR agonists exhibit antiestrogenic and antitumorigenic activities in human breast cancer cells, the rodent uterus and breast. In contrast, a recent study showed that 3,3',4,4'-tetraCB bound the estrogen receptor (ER) and exhibited ER agonist activities, and we therefore have reinvestigated the estrogenic and antiestrogenic activities of 3,3',4,4'-tetraCB. Our results showed that 3,3',4,4'tetraCB and a structurally related analog, 3,3',4,4',5-pentaCB, did not bind the mouse uterine or human ER, did not induce proliferation of MCF-7 or T47D human breast cancer cells or induce reporter gene activity in cells transfected with E2-responsive constructs derived from the creatine kinase B (pCKB) or cathepsin D (pCD) gene promoters. Moreover, 3,3',4,4'-tetraCB and 3,3',4,4',5-pentaCB did not induce an increase in uterine wet weight, peroxidase activity or progesterone receptor binding in the 21-25-day-old female B6C3F1 mouse uterus. In contrast, both compounds inhibited 17beta-estradiol (E2)-induced cell proliferation and transactivation in MCF-7/T47D cells and uterine responses in B6C3F1 mice; surprisingly inhibition of E2-induced reporter gene activity was not observed in T47D cells transfected with pCKB, and this was observed as a cell-specific response with other AhR agonists. Additionally, 3,3',4,4'-tetraCB significantly inhibited mammary tumor growth in female Sprague-Dawley rats initiated with 7,12-dimethylbenzanthracene. Our results indicate that 3,3',4,4'-tetraCB does not exhibit ER agonist activity but exhibits a broad spectrum of antiestrogenic responses consistent with ligand-mediated AhR-ER crosstalk.
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PMID:3,3'4,4'-Tetrachlorobiphenyl exhibits antiestrogenic and antitumorigenic activity in the rodent uterus and mammary cells and in human breast cancer cells. 993 58


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