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)

Cathepsin D was purified from porcine spleen to near homogeneity as determined by gel electrophoresis. The isolation scheme involved an acid precipitation of tissue extract, DEAE-cellulose and Sephadex G-200 chromatography, and isoelectric focusing. The end product represented about a 1000-fold purification and about a 10% recovery. The purified enzyme was the major isoenzyme, which represented 60% of cathepsin D present in porcine spleen. Two minor isoenzymes of cathepsin D were present in small amounts. The purified enzyme resembled porcine pepsin in molecular weight (35,000), amino acid composition, and inactivation by specific pepsin inactivators. The pH activity curve of the purified enzyme showed two optima near pH 3 and 4. The relative activities at these optimal pH values were affected by salt concentration. Experimental evidence indicated that the two-optima phenomenon is a property of a single enzyme species.
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PMID:Purification and properties of cathepsin D from porcine spleen. 0 60

Psoriatic scale proteases were found to be extracted effectively in salt solution (1 mol/l) containing Triton X-100 (5 g/l). The extraction in dilute buffer or sucrose yielded low activities. The acid (0.25 N H2SO4) and KSCN (2 mol/l) solutions effectively extracted plasminogen activator. Fibrinolysin was most active in salt (1 mol/l KCl) and in KSCN (2 mol/l) extracts. Psoriatic scale proteases were fractionated by Sephadex G-100 gel filtration and further by DEAE cellulose chromatography. Five different enzyme preparations were obtained. The first preparation, resembling cathepsin D, effectively hydrolysed hemoglobin at pH 3.5 and casein at pH 5.8 and was insensitive to protease modifiers. The second preparation effectively hydrolysed trypsin substrates (AGLME, TAME, BAEE and BANA) and also histone and casein at pH 7.2 and was inhibited by protease inhibitors, TLCK and E-600. The third preparation hydrolysed histone and casein at pH 10.2 and was effectively inhibited by E-600 and partially by protease inhibitors and TPCK. The fourth preparation, resembling cathepsin B1, hydrolysed BANA and BAEE at pH 5.8 and was activated by SH-reagents and EDTA. The fifth enzyme preparation hydrolysed ATEE and was inhibited by E-600 and TPCK. Plasminogen activator was found mainly in the second enzyme preparation and fibrinolysin activity in the third and fifth enzyme preparations. The second, third and fifth enzyme preparations were different from the enzymes found in healthy human skin. The proteases of psoriatic scale resemble those of tissue and cell cultures undergoing rapid cell division. The possible role of proteases in the increased cell division in psoriasis plaque is discussed.
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PMID:Human skin proteases. Fractionation of psoriasis scale proteases and separation of a plasminogen activator and a histone hydrolysing protease. 0 31

The lysate of the glycogen-induced macrophages in rat peritoneal exudate was fractionated by centrifugation and extraction into a water extract, 1 M KCl extract and residue fractions. Approximately 50% of the neutral protease activity toward casein in the lysate was recovered in the KCl extract fraction, which was practically devoid of acid protease, cathepsin D. The pH optimum of the neutral protease toward casein and urea-denatured hemoglobin was pH 8.5. The activity was inhibited strongly by DFP or chymostatin and only partially by HgCl2 or PCMB. Addition of a salt to the reaction medium caused enhancement of the activity with an optimum concentration of 0.25 M: KCl, KBr, KI, NaCl, NaBr, NaI, and MgCl2 were all almost equally effective. When the enzyme preparation was filtered through a column of Sephadex G-75 gel in the presence of 1 M KCl, a larger molecular weight fraction at the void volume was obtained in addition to a smaller molecular weight fraction showing a caseinolytic activity insensitive to KCl concentration. The former was found to have a specific inhibitory effect on the latter activity.
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PMID:The occurence of a neutral protease and its inhibitor in rat peritoneal macrophages. 1 54

Lucite chambers, applied to antral and proximal duodenal mucosae with blood supply intact, were used to compare ionic flux and the total, labilized activity of several acid hydrolases including cathepsin D, alpha and beta-galactosidase, beta-N-acetyglucosaminidase, arylsulfatase, and acid phosphatase. Insorption of H+ ion by the antrum is increased by the application of aspirin-acid-salt solution, which also stimulates acid hydrolase activity; acute erosions develop very rapidly. On the other hand, H+ ion is much more rapidly removed from chambers applied to the duodenal mucosa, isolated by the chamber from bile and pancreatic secretions. The same aspirin-acid-salt solution reduces net H+ ion loss from the duodenal chamber, depresses levels of the acid hydrolases, and no ulcers develop.
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PMID:Effect of aspirin on ionic movement and acid hydrolase activity of explants of canine antral and duodenal mucosae. 23 98

1. Renal and cerebral vascular lesions occurred more often and earlier in spontaneously hypertensive rats (SHR) given a high salt diet than in SHR given a normal diet. 2. Kidney renin activity was low during high salt loading; the kidney renin activity of rats with hypertensive renal vascular lesions was moderately elevated. Kidney renin activity or cathepsin D activities were higher in stroke-prone SHR (SHRSP) aged 9 months than in stroke-resistant SHR (SHRSR). 3. beta-Glucuronidase, cathepsin D and deoxyribonuclease activities were greater in the kidney of Wistar/Kyoto (WK) rats or SHR when there were hypertensive vascular lesions. These three enzyme activities were also greater in the aorta of SHR aged 13-14 months than in the aorta of WK rats. 4. It was supposed that kidney renin activity and lysosomal enzyme activities were related to hypertensive vascular lesions.
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PMID:Vascular lesions in hypertensive rats under salt loading: kidney renin and lysosomal enzymes. 107 69

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 series of primate renin inhibitors containing difluorocarbinol and difluoroketone groups at the P1-P1' position have been synthesized and studied both in vitro and in vivo. In vitro, the compounds were evaluated as inhibitors of monkey renin and the closely related aspartic proteinase, cathepsin D (bovine), as a measure of enzyme selectivity. Interestingly, the difluoroketone derivatives showed greatly reduced selectivity compared with the corresponding alcohols. However, selectivity could be enhanced by judicious choice of other substituents. Sites influencing selectivity, included not only P2, which is well-known to strongly affect selectivity, but also the P4, P1-P1', and P2' sites. These results make possible the design of inhibitors with a greater selectivity for either renin versus cathepsin D. In vivo several of the compounds in the difluoroketone series have shown good oral activity in the salt depleted normotensive cynomolgus monkey model.
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PMID:Design and synthesis of potent, selective, and orally active fluorine-containing renin inhibitors. 173 31

A series of renin inhibitors with novel modifications at the P2 site has been prepared. Structure-activity relationships reveal that for a particular P2 fragment the in vitro potency is highly dependent on the nature of the P2' portion in addition to the P1-P1' group. The length of the P2 side chain and choice of epsilon-N P2 substitution have been found to be important for in vitro potency although the degree of unsaturation in the P2 side chain is not particularly significant. Molecular modeling studies have shown that it is possible for the P2 side chain to interact unfavorably with the P2' binding site. It has been possible to control the specificity for renin over cathepsin D by correct modification at the P2' and P1-P1' sites. Variations at the P4 site have been utilized to lower the log P values of these renin inhibitors while maintaining high potency. Compound 42, which exhibited an IC50 of 3.70 nM, log P of 2.3, and showed high specificity for renin, was selected for further studies. It was found to be very stable under neutral, acidic, and basic conditions. In simulated intestinal juice, compound 42 had a half-life of 37 min while it was virtually unaffected by simulated gastric juice after 4 h. Compound 42 produced a significant hypotensive response upon intravenous administration to the salt-depleted normotensive cynomolgus monkey.
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PMID:New inhibitors of human renin that contain novel replacements at the P2 site. 190 10

Obstructive lymphedema is a pathologic condition resulting in the accumulation and stagnation of serum proteins in the lymphatics and interstitial spaces. In a canine model of obstructive lymphedema, one limb was rendered lymphedematous, and various biochemical parameters were determined in this and an unaffected control limb. Both lymph and interstitial fluid had significantly decreased acid proteinase activity (comprising mostly cathepsin D-like enzymes) and neutral proteinase activity (comprising metallo, sulfhydryl, and serine proteinases, and collagenase). Possible reasons for these decreases could be: (1) saturation of macrophages and their surrounding environment with whole or partially digested proteins, or (2) elevation in the levels of circulating inhibitors like alpha 2-macroglobulin. The lymphedematous skin was significantly thicker than control skin and had elevated levels of collagen. However, unlike some fibrotic conditions, the relative proportions of types I, III, and V collagen, as determined by pepsin solubilization and neutral salt fractionation of the collagen fibrils, were similar to those found in normal skin. It is speculated that a decrease in the breakdown of collagen by collagenase and a continuing synthesis of collagen by fibroblasts led to an imbalance in favor of collagen deposition in the skin.
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PMID:Protein metabolism and fibrosis in experimental canine obstructive lymphedema. 244 62

The distribution of tryptase in various human tissue high-salt extracts (skin, lung, pancreas, liver, kidney, and spleen) was studied. Tryptase activity was compared with tissue histamine concentration, chymase activity, and cathepsin D, and histamine-N-methyltransferase (HMT) activities. Tryptase activity, found biochemically in tissue extracts, was localized in tissue sections by an enzyme-histochemical method using peptide 4-methoxy-2-naphthylamide substrates and Fast Garnet GBC as the chromogen. The highest levels of tryptase activity were found in lung and skin extracts. Liver, kidney, and spleen extracts displayed only a little activity. The distribution of histamine was similar to that of tryptase, whereas distributions of cathepsin D and HMT were quite different from that of tryptase. High-salt extracts of lung contained no detectable chymase activity, but in skin extracts this activity was high. Using an enzyme-histochemical method, the tryptase activity in tissue sections seemed solely to be confined to cells, which were granular and Giemsa positive after the red azo dye had been removed with Tween 20. Skin and lung sections contained the highest number of positively stained cells. The inhibition properties of tryptase, found in both tissue extracts and sections, and the substrate profile in tissue sections were identical. Human leukocyte preparation was negative for tryptase when stained enzyme-histochemically. The present results suggest that tryptase in human tissues is found only in the mast cells. The enzyme seems to be identical in the various human tissues studied because the different high-salt extracts were immunologically cross-reactive when tested with a rabbit polyclonal antibody against skin tryptase.
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PMID:Biochemical and histochemical evaluation of tryptase in various human tissues. 267 65


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