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)

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

Cytosoluble 100,000 X g extracts from Plasmodium berghei or Plasmodium falciparum infected red blood cells were shown to hydrolyze erythrocyte spectrin. By Fast Protein Liquid Chromatography (FPLC), these enzymes were purified and exhibited a pI of 4.5 and Mr of 37,000 using SDS-PAGE under reducing conditions. An immunochemical enzyme assay using anti-spectrin antibodies was developed. The optimal activity using spectrin as substrate was at pH 5.0, and the enzymes were strongly inhibited by HgCl2, ZnCl2, chymostatin, leupeptin and aprotinin, and moderately by pepstatin. These properties of the Pf37 and Pb37 proteases differ from the Plasmodium lophurae and P. falciparum 'cathepsin D-like' enzymes and from the serine or cysteine neutral proteases previously described in P. falciparum and P. berghei infected red blood cells. While the Pf37 and Pb37 enzymes cleaved spectrin preferentially, degradation of band 4.1 was also observed with high concentration of enzyme. The parasite origin of the Pf37 protease was clearly demonstrated, since purified radiolabeled enzyme was active on spectrin. A high-molecular-weight polymer (greater than 240 kDa) was often observed on incubating purified spectrin and Pf37 protease. The breakdown of erythrocyte cytoskeletal components could be of interest in the release of merozoites from segmented schizonts or during the process of invasion of erythrocytes by merozoites.
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PMID:Purification and characterization of 37-kilodalton proteases from Plasmodium falciparum and Plasmodium berghei which cleave erythrocyte cytoskeletal components. 218 48

Protein breakdown in submandibular glands rendered hypertrophic by amputation of the lower incisor teeth in rats was investigated. Reduced protein breakdown was observed in the hypertrophic gland tissues, and was found to be inhibited by 20 mM epsilon-amino-n-caproic acid, an inhibitor of serine protease, and 50 microM leupeptin, an inhibitor of trypsin, plasmin, papain and cathepsin B, but not by 2 mM PMSF (phenylmethylsulfonyl fluoride), an inhibitor of serine protease, 10 microM pepstatin, an inhibitor of cathepsin D and 20 microM antipain, an inhibitor of cathepsin A and B. These results suggest that some serine proteases and leupeptin-sensitive proteases (presumably cathepsin B) participate in protein breakdown in hypertrophic gland tissues, and that hypertrophy of the submandibular glands is closely related to the reduced protein breakdown in these tissues.
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PMID:Protein breakdown in submandibular glands rendered hypertrophic by amputation of lower incisor teeth in rats. 223 Sep 61

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 effect of alpha 2-macroglobulin, one of the major antiproteinases in the plasma of vertebrates, on the action of the aspartic proteinases chymosin, cathepsin D and cathepsin E towards peptide and protein substrates at pH 6.2 was examined. Activities towards protein substrates were blocked, thus demonstrating that alpha 2-macroglobulin can inhibit aspartic proteinases, in addition to serine proteinases, cysteine proteinases and metalloproteinases.
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PMID:Inhibition of aspartic proteinases by alpha 2-macroglobulin. 247 14

The objectives of this study were to examine effects of a beta-adrenergic agonist (cimaterol) on growth and muscle development in rabbits and to examine cimaterol's effects on myofibrillar protein degradation (MPD) and on activities of several proteolytic enzymes including the calcium-dependent proteinases (CDP). Twelve New Zealand White rabbits were assigned to either control diets or to diets containing cimaterol for 35 d, after which they were killed and effects on performance and tissue weight gains were determined. Urine was collected from d 21 through 28 from each rabbit for assessment of N tau-methylhistidine (NMH) excretion. Cimaterol increased rates of gain, efficiency of gain and skeletal muscle weights. Enhancement in muscle weight was associated with an increase in total DNA and with a reduction in NMH. Cimaterol did not affect activities of cathepsin B, cathepsin D or neutral serine proteinase, but it reduced activities of the millimolar and micromolar forms of the CDP by 58 and 57%, respectively, and it reduced activity of the inhibitor of the CDP (calpastatin) by 52%. Cimaterol-dependent myofibrillar protein accretion was likely mediated, at least in part, by a reduction in MPD. The change in MPD was associated with a reduction in muscle CDP activities. Cimaterol-dependent muscle hypertrophy therefore may involve changes in calcium-dependent proteolysis of myofibrillar proteins. The significance of the effects of cimaterol on calpastatin activity is not known.
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PMID:Effects of cimaterol on rabbit growth and myofibrillar protein degradation and on calcium-dependent proteinase and calpastatin activities in skeletal muscle. 248 86

A high percentage of the total tyrosinase found in Harding-Passey mouse melanoma occurs as a soluble form. This paper shows that melanosomal tyrosinase can be solubilized by several endogenous proteases to yield active tyrosinase. This enzyme, once proteolytically solubilized, can be further degraded, leading to enzyme inactivation. The nature and specificity of the main proteases involved in the solubilization process change depending on the size and necrosis stage of the tumour. Cathepsin B could be the main protease responsible for the solubilization in small tumours (less than 0.5 g). Large tumours are rich in necrotic cells, and cathepsin D and serine-proteases are the main hydrolytic enzymes involved in the proteolytic action on melanosomes. These results support the view that the high activity of tyrosinase found in the soluble fraction of malignant melanoma is mainly an artefact resulting from degradation of melanosomes by a variety of endogenous proteases, rather than the result of the actual occurrence of high levels of an independent cytosolic isozyme.
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PMID:Action of endogenous proteases on the distribution of tyrosinase isozymes in Harding-Passey mouse melanoma. 250 24

S-S cross-linking enzyme, skin sulfhydryl oxidase (SSO), catalyzes the formation of disulfide bonds from sulfhydryl groups in skin. The activity of SSO was detected in differing amounts in each of the four layers--stratum corneum, stratum granulosum, stratum spinosum with basal cell layer, and dermis--of cow snout skin, with the highest specific activity being recorded in the stratum granulosum. SSO was stimulated to 130-150% of its initial activity by treatment with 1 mg/ml trypsin, chymotrypsin, or urokinase, but was not affected by plasmin or cathepsin D. These findings suggest that SSO may be activated by some kinds of serine proteases during the keratinocyte autolysis process in the stratum granulosum. SSO showed the highest activity with the addition of 5 microM of Cu2+. The atomic absorptive analysis of purified SSO showed 0.5 atoms of Cu in one molecule of SSO. From these findings, it was determined that Cu2+ was essential for the activity of SSO. The molar ratio of the disappearance of DTT, consumption of O2, and production of H2O2 during the enzyme reaction was 1:1.05:0.89. From these findings, the reactions catalyzed by SSO is suggested to be represented by the following equation: (table; see text).
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PMID:[Localization in skin, activation and reaction mechanisms of skin sulfhydryl oxidase]. 258 80

Standard immunoperoxidase techniques were used to investigate the distribution of the intracellular proteinase cathepsin D, two serine proteinase inhibitors--alpha 1-antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-AChy)--and plasma fibrin stabilizing factor XIII (FXIII) in paraffin-embedded tissues from early and late intrauterine pregnancy and ectopic pregnancy. Localization of cathepsin D, alpha 1-AT, and alpha 1-AChy was identical in ectopic and intrauterine gestation: there was labeling of villous syncytiotrophoblast and a proportion of Hofbauer cells but no labeling of villous cytotrophoblast. The majority of interstitial extravillous trophoblast yielded negative results, but alpha 1-AT and alpha 1-AChy were consistently demonstrated in endovascular trophoblast. FXIII was not found in any trophoblast population but was demonstrated in Hofbauer cells, stromal fibroblasts, and interstitial dendritic cells. Granular, extracellular FXIII reactivity was present among sheets of infiltrating extravillous trophoblast in ectopic pregnancy but only occasionally in early intrauterine pregnancy. The results document further the heterogeneity of trophoblast, with the endovascular trophoblast forming an immunophenotypically distinct population. Furthermore, the pattern of extravillous trophoblastic invasion of maternal tissues in ectopic pregnancy appears to differ from intrauterine pregnancy; the poor decidualization of tubal mucosa in ectopic pregnancy may play a role in this variation.
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PMID:Proteinase and proteinase inhibitor localization in the human placenta. 265 41

Casein-induced amyloidosis in hamsters was found to be of the AA-type, as shown by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis of the major low-molecular weight component of the amyloid fibrils. Levels of serum amyloid A (SAA) and the activities of cathepsin D, beta-N-glucosaminidase, serine esterase, lactate dehydrogenase (LDH) and gamma glutamyl transpeptidase (GGT) were measured in the blood plasma during induction of amyloidosis. During the pre-amyloid phase an increase was observed in all these parameters. During the deposition of amyloid, an increase was observed in the activities of the lysosomal enzymes cathepsin D and beta-N-glucosaminidase, which was significantly correlated with amyloid deposition. Serine esterase activities did not show any relationship to amyloid deposition. LDH and GGT activities were normal in the amyloid phase. SAA levels were lower during amyloid deposition than during the pre-amyloid phase. These findings indicate that a specific release of lysosomal contents from mononuclear phagocytic cells is involved in the pathogenesis of AA-amyloidosis. Amyloid deposition may be the result of: (i) extrusion of intralysosomal protein AA or pre-amyloid, followed by extracellular formation of amyloid fibrils; (ii) secretion of lysosomal enzymes, followed by extracellular cleavage of SAA and subsequent aggregation of protein AA with other components.
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PMID:Activities of lysosomal enzymes and levels of serum amyloid A (SAA) in blood plasma of hamsters during casein induction of AA-amyloidosis. 286 Sep 18


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