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)

The synthesis, accumulation, and cellular distribution of cathepsins E and D during the dimethyl sulfoxide (DMSO)-induced differentiation of Friend erythroleukemia cells were investigated. The cellular levels of cathepsins E and D rapidly increased within 1 day of DMSO induction and then sharply decreased over the next 7 days. Since the cells during 1 day of differentiation were morphologically the same as uninduced cells, the results suggest the importance of these enzymes in more cellular proteolysis for the following committed differentiation. While cathepsin D was present mostly in the sedimentable fraction of cells throughout the differentiation period, the distribution of cathepsin E varied to the stage of differentiation. The ratio of the soluble/sedimentable cathepsin E content was 1.1, 1.4, 0.9, and 0.7 in cells after 0, 1, 4, and 7 days of DMSO treatment, respectively. The maturation of reticulocytes to erythrocytes was accompanied by complete loss of the soluble cathepsin E and of all of the cellular cathepsin D. Immunoblotting analyses revealed that both uninduced and induced cells contained two forms of cathepsin E; a high molecular weight form (82 kDa) which was mainly associated with the sedimentable fraction and a low molecular weight form (74 kDa) which was found largely in the soluble fraction. The distribution of these two forms was not significantly changed throughout the differentiation period, but the 74-kDa protein was completely eliminated with maturation of reticulocytes to erythrocytes. Cathepsin D also appeared in two forms in both uninduced and induced cells; a minor (46 kDa) and a major (42 kDa) form which appear to have a precursor-product relationship.
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PMID:Synthesis and intracellular distribution of cathepsins E and D in differentiating murine Friend erythroleukemia cells. 156 96

Controversy exists whether vascular smooth muscle cells in vivo synthesize renin, thereby providing a critical component of the hypothesized vascular renin-angiotensin system. To examine this question, we enzymatically isolated and pooled the medial layer of thoracic aortas from Sprague-Dawley rats that were either untreated or enalapril treated for 3 days, isolated messenger RNA (mRNA), and performed Northern blot analysis with rat complementary DNA (cDNA) probes for renin, cathepsin D, and cathepsin E. Renin mRNA was detected in kidney but was not detected in aortic smooth muscle from the untreated or enalapril-treated groups. Cathepsin E mRNA was detected in enalapril-treated aorta and kidney, and cathepsin D mRNA was detected in all tissues examined. cDNA was synthesized and subjected to polymerase chain reaction analysis by using primers corresponding in sequence to regions conserved throughout the aspartic proteinases. Cathepsins D and E were amplified from kidney and aortic cDNA. Renin was less consistently amplified from the aortic cDNA and was much less abundant than cathepsin E or cathepsin D. These results suggest that 1) renin mRNA is present in aortic smooth muscle cells in vivo in quantities detectable only after multiple rounds of polymerase chain reaction amplification, 2) renin mRNA is not upregulated in aortic smooth muscle after converting enzyme inhibition, and 3) cathepsins D and E are the predominant aspartic proteinases in aortic smooth muscle.
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PMID:Polymerase chain reaction analysis of renin in rat aortic smooth muscle. 159 70

Proteolytic degradation (processing) of antigen by antigen-presenting cells is a major regulatory step in the activation of a T lymphocyte immune response. However, the enzymes responsible for antigen processing remain largely undefined. In this study we show that cathepsin E, and not the ubiquitous lysosomal cathepsin D, is the major aspartic proteinase in a murine antigen-presenting cell line, A20. This enzyme is localized to a non-lysosomal compartment of the endosomal system in these cells. Functional studies using a highly specific inhibitor of cathepsin E show that this enzyme is essential for the processing of ovalbumin by this cell line. Thus, cathepsin E, whose function was hitherto unknown, may play a major role in antigen processing.
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PMID:Antigen processing for presentation by class II major histocompatibility complex requires cleavage by cathepsin E. 160 Oct 38

1. Five synthetic peptides which together spanned the propart segment of human prorenin were tested for their ability to interact with human renin, pepsin, gastricsin, cathepsin D, cathepsin E, calf chymosin and the aspartic proteinase from Endothia parasitica. 2. While two peptides showed no significant effect with any of the enzymes, a further two were cleaved by several enzymes. 3. Only one (corresponding to the 32P-43P residues in the propart sequence) acted as a weak competitive inhibitor of most of the enzymes.
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PMID:Inhibition of aspartic proteinases by synthetic peptides derived from the propart region of human prorenin. 173 96

Immunocytochemical localization of two distinct intracellular aspartic proteinases, cathepsins E and D, in human gastric mucosal cells and various rat cells was investigated by immunogold technique using discriminative antibodies specific for each enzyme. Cathepsin D was exclusively confined to primary or secondary lysosomes in almost all the cell types tested, whereas cathepsin E was not detected in the lysosomal system. The localization of cathepsin E varied with different cell types. Microvillous localization of cathepsin E was found in the intracellular canaliculi of human and rat gastric parietal cells, rat renal proximal tubule cells, and the bile canaliculi of rat hepatic cells. The immunolocalization of each enzyme in gastric cells were essentially the same in humans and rats. In the gastric feveolar epithelial cells and parietal cells, definite immunolabeling for cathepsin E was observed in the cytoplasmic matrix, the cisternae of the rough endoplasmic reticulum, and the dilated perinuclear envelope. In rat kidney, cathepsin E was detected only in the proximal tubule cells, while cathepsin D was found mainly in the lysosomes of the distal tubule cells but not in those of the proximal tubule cells. These results clearly indicate the distinct intracytoplasmic localization of cathepsins E and D and suggest the possible involvement of cathepsin E in extralysosomal proteolysis that is related to specialized functions of each cell type.
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PMID:An immunocytochemical study on distinct intracellular localization of cathepsin E and cathepsin D in human gastric cells and various rat cells. 179 85

Pregnancy in cattle and sheep can be diagnosed by the presence of a conceptus-derived antigen in maternal serum that is secreted by trophoblast and placental tissue primarily as an acidic component of Mr 67,000. Molecular cloning of its cDNA reveals that the antigen belongs to the aspartic proteinase family and has greater than 50% amino acid sequence identity to pepsin, cathepsin D, and cathepsin E. The inferred sequences of the ovine and bovine polypeptides show approximately 73% identity to each other. Critical amino acid substitutions at the active site regions suggest that both proteins are enzymatically inactive. The antigen is a product of trophoblast binucleate cells that invade maternal endometrium at implantation sites.
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PMID:Identification of the major pregnancy-specific antigens of cattle and sheep as inactive members of the aspartic proteinase family. 194 44

The distribution of cathepsins D and E in leukocytes and erythrocyte ghosts of several mammalian species, and in HL-60 and K-562 cells was examined by means of a combined application of electrophoretic and immunochemical methods. Cathepsin D was found in leukocytes of all species examined, but the distribution of cathepsin E was found to be species-specific: pigs, cows and goats had no cathepsin E activity in leukocytes or erythrocytes at all. In humans, cathepsin E occurred in erythrocytes but not in leukocytes, which contrasted with the guinea pig pattern of its presence in leukocytes and its absence in erythrocytes. No cathepsin E-related enzymes were found in HL-60 or K-562 cells, but these human leukemic cells contained cathepsin D-related enzyme forms that are electrophoretically distinct from normal leukocyte cathepsin D. The present results are inconsistent with the view that cathepsin E may be involved as an essential factor in the biological functions of leukocytes or erythrocytes.
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PMID:Species-specific distribution of cathepsin E in mammalian blood cells. 199 Nov 30

A series of renin inhibitors containing lactam-bridged P1-P1' dipeptide mimetics based on the ACHPA (4(S)-amino-5-cyclohexyl-3(S)-hydroxypentanoic acid) design was studied. The inhibitors were obtained by aldol addition of various lactams with N alpha-Boc-L-cyclohexylalaninal, followed by Boc group removal and acylation with Boc-Phe-His. The aldol diastereomer having the S configuration at the two newly generated stereogenic centers gave optimal enzyme inhibition. Potency was further enhanced in the gamma-lactam ring series by substitution with small hydrophobic groups to mimic the P1' side chain of the renin substrate. Thus, 2(S)-[(Boc-L-phenylalanyl-L-histidyl)amino]-3-cyclohexyl-1(S)-hydroxyl-1 - (1,5,5-trimethyl-2-oxopyrrolidin-3(S)-yl)propane (34) has an IC50 of 1.3 nM in the human plasma renin assay. A variety of substituents on the lactam nitrogen are tolerated and can be used to vary the physical properties of the inhibitor. By using a model of the human renin active site, the conformation of 34 in the enzyme-inhibitor complex is proposed. This modeled conformation is very similar to the solid-state conformation of 2(S)-[(Boc-L-phenylalanyl-L-histidyl)amino]-3-cyclohexyl-1(S)-hydroxyl- 1-(1-methyl-2-oxopyrrolidin-3(S)-yl)propane (36), the structure of which was determined by single-crystal X-ray diffraction analysis. The most potent ACH-PA-lactam renin inhibitors show good selectivity when assayed against other types of aspartic proteinases. By varying the lactam ring substituents, potent and selective inhibitors of cathepsin D and cathepsin E can be obtained.
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PMID:Renin inhibitors containing conformationally restricted P1-P1' dipeptide mimetics. 200 69

Oligonucleotides directed towards the active site regions of aspartic proteases were used as primers for the polymerase chain reaction to identify a unique sequence (asppcr1) from the AtT-20 anterior pituitary corticotrope cell line. Asppcr1 showed the greatest similarity (85% identity) to human cathepsin E [(1989) J. Biol. Chem. 264, 16748-16753]. Northern blot analysis of AtT-20 RNA revealed a single 1.9 kB message. Nuclease protection experiments indicated that asppcr1 mRNA was present in pancreas, spleen, testis and liver at low levels and undetectable in heart and brain. This contrasted with the lysosomal aspartic protease, cathepsin D whose mRNA showed a broader tissue distribution. The restricted message distribution of asppcr1 supports a more specific role for this aspartic protease in aspect(s) of cellular physiology.
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PMID:Homology cloning of aspartic proteases from an endocrine cell line using the polymerase chain reaction. 205 19

The nature and levels of hemoglobin (Hb)-hydrolyzing acidic proteinases including cathepsin D and cathepsin E, which were most active at pH 3.5-4.0, were enzymatically and immunochemically compared between human and rat neutrophils. By subcellular fractionation and immunoprecipitation with discriminative antibodies specific for each enzyme, cathepsin D was shown to be present in the granular content fraction of both human and rat neutrophils and to account for about 35% of the total Hb-hydrolyzing activity. Cathepsin E was observed mainly in the cytoplasmic fraction of rat neutrophils from peripheral blood and peritoneal exudates and accounted for about 65% of the total activity, but it was not detected in human blood neutrophils. Immunoelectron microscopy on rat neutrophils revealed that cathepsin D was exclusively confined to lysosomes, whereas cathepsin E was localized mainly in the cytoplasmic matrix and often in the perinuclear spaces and the rough endoplasmic reticulum. The non-cathepsin D activity in human neutrophils, which represented about 65% of the total activity, appeared to be due to a serine proteinase, since it was inhibited by diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride and was not inhibited by agents specific for aspartic-, cysteine-, or metallo proteinases. The enzyme(s) responsible for this activity was largely associated with the granular membranes, and a half of it could be described as an integral membrane protein on the basis of phase separation with Triton X-114 at 35 degrees C. The levels of these Hb-hydrolases in gingival crevicular fluid from human chronic inflammatory periodontitis patients were examined in order to clarify their participation in the periodontal tissue breakdown.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of hemoglobin-hydrolyzing acidic proteinases in human and rat neutrophils. 208 32


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