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 levels of six lysosomal enzymes (acid phosphatase, beta-acetylglucosaminidase, cathepsin D, beta-galactosidase, arylsulfatase A, and beta-glucuronidase) and four neutral and alkaline hydrolases (esterase, inorganic phyrophosphatase, alkaline phosphatase, and 5'-nucleotidase) were measured in osteoarthritic, rheumatoid and control synovia. All enzyme levels in diseased synovium except esterase values in osteoarthritis were significantly elevated compared with controls. The mean values of the group of acid hydrolases and the group of neutral and alkaline hydrolases in osteoarthritic synovia were 1.9- and 2.0-fold greater than those of control specimens. In rheumatoid synovia, the values were 4.2- and 4.5 fold greater than control for the same enzymes. Levels in rheumatoid synovia were significantly higher than those in osteoarthritic synovia with the exception of 5'-nucleotidase. Only a limited correlation between the extents of inflammation present in the synovia and the levels of a lysosomal marker enzyme (cathepsin D) was observed. These results demonstrate that whatever the mechanism, increased levels of acid hydrolases as well as certain neutral and alkaline hydrolases are present in osteoarthritic and rheumatoid synovia, and these enzymes are probably contained in the synovial lining cells.
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PMID:Acid, neutral, and alkaline hydrolases in arthritic synovium. 0 9

Optimal assay conditions are described for 8 hydrolases of Euglena gracilis var. bacillaris, SM-L1 (streptomycin-bleached) strain, 7 of which have an acid pH-optimum. Acid-phosphatase, beta-galactosidase, beta-glucosidase, b-fucosidase, cathepsin D, RNase, DNase, and an esterase are active in cell homogenates. Amylase has very low activity, and beta-glucuronidase, arylsulfatase, beta, N-acetyl-glucosaminidase, alpha-fucosidase, and alpha- and beta-mannosidase are inactive.
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PMID:Hydrolytic enzymes of Euglena gracilis: characterization and activity as a function of culture age and carbon deprivation. 0 4

Twelve acid hydrolases, 4 near-neutral hydrolases, and alkaline phosphatase were demonstrated in 0.34 M sucrose homogenates of Trypanosoma cruzi strain Y: p-nitrophenylphosphatase and alpha-naphthylphosphatase, with optimum pH at approximately 6.0; alpha=ga;actpsodase. beta=ga;actpsodase. beta=g;icpsodase, N-acetyl-beta-glucosaminidase, cathepsin A and peptidase I and III, with optimum pH between 5.0 and 6.0; and arylsulfatase, cathepsin D, alpha-arabinase and alpha-mannosidase with optimum pH at approximately 4.0. alpha-Glucosidase, glucose-6-phosphatase and peptidase II had optimum pH at approximately 7.0. beta-Glycerophosphatase had a broad pH-activity curve from 4,0 to 7.4, with maximum activity at pH 7.0. The main kinetic characteristics of these enzymes and their quantitative assay methods were studied. No activity was detected for alpha-fucosidase, beta-xylosidase, beta-glucuronidase, elaidate esterase, acid lipase, and alkaline phosphodiesterase.
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PMID:Acid and neutral hydrolases in Trypanosoma cruzi. Characterization and assay. 4 19

The subcellular distributions of acidic (pH 4.5) and neutral (pH 7.5) longchain triacylglycerol lipases (glycerol ester hydrolase, EC 3.1.1.3) of pig liver have been determined. The distribution of the acidic lipase closely paralleled that of the lysosomal marker enzyme, cathepsin D. Approx. 60% of the neutral lipolytic activity resided in the soluble fraction;the distribution of this activity failed to parallel that of marker enzymes for mitochondria, lysosomes, microsomes, or plasma membranes. A method has been developed for purification of the neutral lipase from the soluble fraction by ultracentrifugation. An approximate 90-fold purification was achieved, with recovery of 16% of the initial activity. The partially purified neutral lipase exhibited a pH optimum between 7.25 and 7.5. It required 30 mM emulsified triolein for optimal activity and ceased to liberate fatty acids after 30 min of incubation. The enzymatic activity was destroyed by heating at 60 degrees C. Neutral lipase was inhibited by sodium deoxycholate, Triton X-100 and iodoacetamide. The activity was not inhibited by sodium taurocholate, EDTA, heparin and diethyl-p-nitrophenyl phosphate. Neutral lipase failed to exhibit activity in assay systems specific for lipoprotein lipase, monoolein hydrolase, tributyrinase, and methyl butyrate esterase and showed little or no capacity to hydrolyze chyle chylomicrons or plasma very low density lipoproteins. It is suggested that the function of neutral lipase may be to supply the liver with fatty acids liberated from endogenously synthesized or stored triacylglycerols.
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PMID:Subcellular fractionation, partial purification and characterization of neutral triacylglycerol lipase from pig liver. 23 42

A chymotrypsin-like esterase was purified from beef lung. This lysosomal enzyme, not previously characterized, seemed to be composed of two or more forms with molecular weights of about 52 000. It hydrolysed N-benzoyl-DL-phenylalanine beta-naphthol ester at acid and neutral pH; it polymerized L-phenylalanine methyl ester(Phe-OMe) at neutral pH; and it transferred the Phe-residue from Phe-OMe to hydroxylamine at neutral pH. Phenylmethanesulfonyl fluoride, an inhibitor of hydrolytic enzymes with serine in their catalytic site, inhibited this enzyme, but pepstatin, the cathepsin D (EC 3.4.4.23) inhibitor, did not. Sulfhydryl reagents were not required for activity. Macrophages, especially pulmonary alveolar macrophages, were a rich source of this esterase, so it is likely that the enzyme purified from lung came from its macrophages. The esterase hydrolysed and transferred monoamino acid esters, especially those of the aromatic type. Cathepsin C, the dipeptidyl peptide hydrolase (EC 3.4.14.1), acted only on dipeptide esters and amides. Pancreatic chymotrypsin acted on both monoamino acid and dipeptide esters. The chymotrypsin-like esterase did not hydrolyse hemoglobin, casein, or plasma albumin. Thus its proteolytic activity, if present, must be limited to specific substrates, as yet unknown.
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PMID:Macrophage esterase: identification, purification and properties of a chymotrypsin-like esterase from lung that hydrolyses and transfers nonpolar amino acid esters. 24 Apr 26

The influence of sunflower and olive oils and their combination with cholesterol on the activity of lysosomal hydrolases and lipid peroxidation (LPO) in the mucosa of the mouth and jejunum was studied. It was shown that in the presence of cholesterol in the oral mucosa the activity of N-acetylhexosaminidase increased and there was a tendency to decreasing cathepsin D and acetyl esterase activity, and LPO processes were found to be suppressed. Cathepsin D and B activities in the jejunum mucosa increased in response to cholesterol administration. The changes revealed in the activities of N-acetylhexosaminidase, proteinase, acetyl esterase, catalase and glutathione peroxidase in the oral mucosa, as well as cathepsins in the jejunum depend on the character of lipid additives.
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PMID:[A comparative study of the effects of vegetable oils and cholesterol on enzymes of the mouth and jejunal mucosae]. 151 58

The authors suggest a highly sensitive rapid and simple method for measuring esterase activities of bovine pancreatic chymotrypsin, human neutrophilic cathepsin D, and elastase, and of human blood serum chymotrypsin-like esterase and elastase-like esterase activities, with fluorogenic synthetic ethers, amino acid derivatives, employed as substrates: N-benzoxycarbonylphenylalanine 4-methylumbelliferyl ester (Z-Phe-OMC) and tret-butyloxycarbonyl-1-alanine 4-methylumbelliferyl ester (BOC-Ala-OMC).
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PMID:[Determination of the esterase activity of serine proteinases using synthetic substrates]. 171 86

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

Considerable progress has been made in the localization of chemical substances within the gas-exchange zones of vertebrate lungs since cytochemical techniques suitable for use with the electron microscope have been developed. The light microscope, an instrument with an effective resolution limit of about 0.2 micron, is ill-suited for studying regions such as these where small tissue elements are arranged in a complex manner. A wide range of acid hydrolases have been detected in the vacuoles and dense bodies of alveolar macrophages by means of cytochemical techniques. The enzymes demonstrated in this way include acid phosphatase, aryl sulphatase, cathepsin D, beta-glucuronidase, acetyl glucosaminidase, nonspecific esterase, dipeptidyl peptidase II and dipeptidyl peptidase IV. Such enzymes are, of course, to be expected in the lysosomes of cells which have a primary phagocytic role. Nevertheless, it must be confessed that very little is yet known about the actual mechanism of phagocytosis or of the fate of the digested material. It is fortunate, however, that some of the tools which are likely to be of value in research on these aspects of macrophage function are currently being developed. Of particular interest in this connection are the immunocytochemical techniques which permit the localization of surface-associated antigens and intracellular contractile proteins. It must be emphasized that phagocytosis is not the only function of macrophages in the gas-exchange zone of the lung. These cells are thought to be involved in the presentation of exogenous antigenic material to the reactive cells of the lymphoid system. Recent research has also indicated that mammalian alveolar macrophages synthesize a diverse range of substances. Furthermore, the elastases associated with pulmonary macrophages are now thought to be involved in the pathogenesis of emphysema. All of the above-mentioned activities are of great biological and clinical significance and, consequently, merit the cytochemists' attention in future. The epithelial lining of the greater part of the pulmonary gas-exchange area is composed of type I pneumonocytes. In terms of ultrastructure, these are very specialized cells; their extensive and highly-attenuated cytoplasmic processes form the outer layer of the air-blood barrier. No special carrier systems have been identified within type I pneumonocytes and this is in keeping with the claims that oxygen is transferred across the alveolar tissue barrier by a process of simple diffusion. Type II pneumonocytes, in contrast, have considerable metabolic activity.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Cytochemistry of the gas-exchange area in vertebrate lungs. 355 66

Homogenates of cultured rat embryo fibroblasts have been assayed for acid phosphatase, N-acetyl-beta-glucosaminidase, cathepsin D, acid deoxyribonuclease, cytochrome oxidase, NADH cytochrome c reductase, 5'-nucleotidase, inosine diphosphatase, acid pyrophosphatase, neutral pyrophosphatase, esterase, catalase, cholesterol, and RNA. The validity of the assay conditions was checked. Neutral pyrophosphatase is a readily soluble enzyme. Acid hydrolases, except acid pyrophosphatase, are particle-bound enzymes, which exhibit a high degree of structural latency. They are activated and solubilized in a parallel fashion by mechanical treatments and tensio-active agents. Catalase is also particle-bound and latent; activating conditions stronger than those for hydrolases are required to activate the enzyme. Acid pyrophosphatase, 5'-nucleotidase and inosine diphosphatase are firmly particle-bound, but not latent; they are not easily solubilized. In differential and isopycnic centrifugation, the latent hydrolases, cytochrome oxidase and catalase dissociate largely from each other; this suggests the occurrence of lysosomes and peroxisome-like structures besides mitochondria. The distribution patterns of 5'-nucleotidase and cholesterol are largely similar; digitonin influences their equilibrium density to the same extent; these two constituents are thought to be related to the plasma membrane. Inosine diphosphatase and acid pyrophosphatase are also partially associated with the plasma membrane, although some part of these enzymic activities probably belongs to other structures. NADH cytochrome c reductase is associated partly with the endoplasmic reticulum, partly with mitochondria.
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PMID:Analytical fractionation of homogenates from cultured rat embryo fibroblasts. 437 90


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