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 amino acid sequences near the glycosylation sites and the oligosaccharide structures have been determined for the lysosomal protease cathepsin D from porcine spleen. Cathepsin D light and heavy chains were separately digested with proteases and the glycopeptides were purified. A single sequence was constructed from the amino acid sequence of the light chain glycopeptides which is: Tyr-Asn-Ser-Gly-Lys-Ser-Ser-Thr-Tyr-Val-Lys-Asn(CH2O)-Gly-Thr-Thr-Phe. A single glycopeptide sequence was also obtained for the heavy chain: Lys-Gly-Ser-Leu-Asp-Tyr-His-Asn(CH2O)-Val-Thr-Arg-Lys-Ala-Tyr. The light chain sequence is homologous with the sequence of porcine pepsin from residues 56 to 71. The heavy chain sequence is homologous with the pepsin sequence from residues 176 to 189. Thus, the 2 oligosaccharide-linked asparagines in cathepsin D correspond to residues 67 and 183 in pepsin and other homologous aspartyl proteases. These positions are located on the surface of the crystal structures of aspartyl proteases. Five oligosaccharides linked to Asn-67 were separated and their structures determined with proton NMR. Four major oligosaccharides are structural variants from the high mannose-type having 3, 5, 6, and 7 mannoses, respectively. A minor structure contained a third GlcNAc. Three oligosaccharide structures were found linked to Asn-183. Two major oligosaccharides are of the high mannose-type each with 5 mannose residues. One of the two contains a fucose linked to a GlcNAc. A third, very minor oligosaccharide contains galactose.
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PMID:Oligosaccharide units of lysosomal cathepsin D from porcine spleen. Amino acid sequence and carbohydrate structure of the glycopeptides. 682 41

Rates of proteolysis by hearts obtained from alloxan diabetic rats and perfused as working preparations with buffer simulating control sera were accelerated 30% above identically perfused control hearts. The total homogenate activities of cathepsin D and beta-N-acetylglucosaminidase, assayed in the presence of Triton X-100, decreased 15-35% in diabetic heart, but the activities of these lysosomal enzymes assayable in the absence of detergent were unchanged in the diabetic tissue. The effects of diabetes were examined further by centrifugation of particulate fractions from subtilisin-treated hearts of control and diabetic rats on polyvinylpyrrolidone-coated colloidal silica (Percoll) gradients. Two species of lysosomes were resolved on the basis of their densities. Both dense and buoyant lysosomes accumulated radioactivity when hearts were exposed to [14C]phenylalanine methyl ester. Dense lysosomes (1.06-1.09 g/ml) sedimented with mitochondria while buoyant lysosomes banded with Golgi and sarcolemmal particles (1.02-1.03 g/ml). When particulate fractions of hearts from diabetic animals were layered on the Percoll gradients, total activities of beta-N-acetylglucosaminidase and cathepsin D were decreased from control in buoyant lysosomes, but unchanged in dense lysosomes. These results demonstrated that the increase in proteolysis in the diabetic heart was associated with decreased total activity and latency of cathepsin D and beta-N-acetylglucosaminidase and an increased proportion of dense lysosomes in the particulate fraction.
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PMID:Effects of diabetes on cardiac lysosomes and protein degradation. 686 24

Ten analogs of the peptide A-Phe(NO2)-Phe-Val-Leu-B were synthesized and tested as substrates for cathepsin D and pepsin. The best substrate found for cathepsin D, Phe-Ala-Ala-Phe(NO2)-Phe-Val-Leu-OM4P (kcat = 2.9 s-1; Km = 7.1 microM), has the largest kcat/Km value (408 mM-1 s-1) reported to date for this enzyme. The effect of peptide structure on solubility and kinetic parameters is discussed. The peptide provides a useful new substrate for continuous assay of cathepsin D.
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PMID:An improved cathepsin-D substrate and assay procedure. 686 96

Cathepsin D inactivated aldolase at pH values between 4.2 and 5.2; the chloride, sulphate or iodide, but not citrate or acetate, salts of sodium or potassium accelerated the rate of inactivation. Cathepsin D cleaved numerous peptide bonds in the C-terminus of aldolase, but the major site of cleavage in this region was Leu354-Phe355. The most prominent peptide products of hydrolysis were Phe-Ile-Ser-Asn-His-Ala-Tyr and Phe-Ile-Ser-Asn-His. Up to 20 amino acids were removed from the C-terminus of aldolase, but no further degradation of native aldolase was observed. By contrast, extensive degradation of the 40 000-Mr subunit was observed after aldolase was denatured. The cathepsin D-inactivated aldolase cross-reacted with antibodies prepared against native aldolase and had the same thermodynamic stability as native aldolase, demonstrated by differential scanning calorimetry and fluorescence quenching of tryptophan residues. Furthermore, the cathepsin-modified and native forms of aldolase were both resistant to extensive proteolysis by other purified cellular proteinases and lysosomal extracts at pH values of 4.8-8.0.
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PMID:Action of cathepsin D on fructose-1,6-bisphosphate aldolase. 688 56

Two types of cathepsin D (cathepsins D-I and D-II) were purified from rhesus monkey lung to homogeneity as judged from disc gel electrophoresis. Cathepsin D-I was purified about 2,000-fold with a 5.1% yield while cathepsin D-II was purified about 2,300-fold with a 14.3% yield. Both cathepsins D were rich in the lysosome fraction of the lung, but appeared to be present in part extracellularly. Both showed a molecular weight of about 35,000 on Sephadex G-100 chromatography, and about 41,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cathepsin D-I showed the maximal activity on bovine hemoglobin and albumin at pH 3.4 and 4.0, respectively. It was most stable in the pH range of 5 to 7, but was rather unstable outside this pH range. Cathepsin D-II was quite similar in properties to that from Japanese monkey lung (Moriyama, A. & Takahashi, K. (1978) J. Biochem. 83, 441-451), and was remarkably stable in the pH range of 1-9. Under the conditions used, it retained at least 80% of the original activity when incubated at 37 degrees C for 20 h in this pH range. This stability seems to allow cathepsin D-II to be fairly active even at pH 1.0. Both cathepsins D acted on protein substrates fairly similarly and hydrolyzed hemoglobin most rapidly among the proteins tested. They did not hydrolyze N-acetyl-L-phenylalanyl-3,5-diiodotyrosine. Upon incubation with the oxidized B-chain of insulin, both cathepsins D hydrolyzed the Ala-Leu, Leu-Tyr, Tyr-Leu, Phe-Phe, and Phe-Tyr bonds at both pH 3.0 and 5.0. In addition, cathepsin D-II hydrolyzed the Leu-Val and Tyr-Thr bonds at pH 3.0 and the Val-Asn bond at pH 5.0. Both cathepsins D were inactivated by acid protease-specific inhibitors such as pepstatin, 1,2-epoxy-3-(p-nitrophenoxy)propane, p-bromophenacyl bromide, and diazoacetyl-DL-norleucine methyl ester, although cathepsin D-II was much less susceptible to these reagents except p-bromophenacyl bromide.
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PMID:Cathepsins D from rhesus monkey lung. Purification and characterization. 699 76

Initial cleavage sites of native insulin at a pH of about 3 and stereospecificity were investigated by fungal carboxyl proteinases (EC 3.4.23.6) from ASpergillus sojae, a species of fungi imperfecti, and Pycnoporus coccineus (formerly designated Trametes sanguinea), a wood deteriorating Basidiomycete, respectively. Fungal carboxyl proteinases were used as a model of vertebrate insulin degradation. A. sojae carboxyl proteinase I primarily hydrolyzed two peptide bonds located on the surface of native insulin monomer, the B16-B17 (Tyr-Leu) and B24-B25 (Phe-Phe) bonds, and secondarily the buried bonds, A15-A16 (Gln-Leu), B15-B16 (Leu-Tyr) and B14-B15 (ala-Leu), at pH 3.2 and 30 degree C. The initial cleavage sites of A. sojae carboxyl proteinases I towards native insulin were not identical with the initial cleavage sites towards the oxidized B chain of insulin. P. coccineus carboxyl proteinase Ia selectively hydrolyzed B14-B15 (Ala-Leu), B16-B17 (Tyr-Leu) and B24-B25 (Phe-Phe) bonds in the native insulin at pH 2.7. Based on these findings we suggest that the stereospecificity of the fungal carboxyl proteinases is similar to that of cathepsin D (EC 3.4.23.5), and that the synthesis and degradation of insulin may occur in microorganisms.
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PMID:Initial sites of insulin cleavage and stereospecificity of carboxyl proteinases from Aspergillus sojae and Pycnoporus coccineus. 703 82

Two methods have been developed to discriminate simultaneously between the main part of cysteine proteinase activity (cathepsin L) and all aspartic proteinase activity (mainly cathepsin D) in rat organs, using Z-Phe-Phe-CHN2 which at 5 mumol/l completely inhibits cathepsin L from rat liver and, on the other hand, pepstatin which at 0.5 mumol/l completely inhibits cathepsin D. Substrates are double-labeled cytosol proteins from rat liver at pH 3.0 or azocasein in 3 mol/l urea at pH 5.0. Several organs from rat, pigeon, frog and carp have been investigated using these methods. Especially kidneys from rat, frog and carp contain a high Z-Phe-Phe-CHN2 inhibited activity. Investigating the different liver cell types we could confirm earlier findings that Kupffer cells and endothelial cells contain more pepstatin inhibited activity than parenchymal cells.
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PMID:Inhibition of cysteine proteinase activity by Z-Phe-Phe-diazomethane and of aspartic proteinase activity by pepstatin in different organs from some animals and isolated cells from rat liver. 705 5

We labeled proteins with [14C]phenylalanine in rats breathing air and assessed the rate of proteolysis in the isolated ventilated lung by measuring the accumulation of [14C]phenylalanine in the medium perfusing the lung. Ventilation with 0% O2 decreased the rate of proteolysis and the ATP content in the lung 60%. Medium from lungs ventilated with 0% O2, when used to perfuse lungs ventilated with 95% O2, decreased the rate of proteolysis 60% without lowering the ATP content of the lung. Correcting the pH of "used" medium or dialyzing used medium did not decrease its ability to inhibit proteolysis. Used medium from nonhypoxic lungs, or exogenous lactate (50 mM), diminished proteolysis only 20%. In a cell-free system the degradation by cathepsin D of radioactive lung proteins and radioactive hemoglobin was decreased by used medium from hypoxic lungs. We conclude that the hypoxic perfused lung releases a factor(s) that decreases the rate of proteolysis in nonhypoxic lungs and that this factor may be a protease inhibitor.
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PMID:Proteolysis in the rat lung: hypoxia and evidence for an inhibitor of proteolysis. 727 Jun 77

Procathepsin L, the precursor to a powerful lysosomal cysteine proteinase, has been purified to apparent homogeneity from guinea pig spermatozoa, a novel and previously unrecognized source of this catalytically active zymogen. In the range of pH 5.0, procathepsin L (39,000 M(r)) readily self-processed yielding a mature, single-chain proteinase (29,000 M(r)) and an intact propeptide (10,000 M(r)) by what appeared kinetically to be an intramolecular reaction mechanism. These characteristics resembled those reported for the "major excreted protein" (MEP) of malignantly transformed mouse fibroblasts-a protein that has been characterized as the precursor to the mouse analog of human cathepsin L (B. R. Troen, S. Gal, and M. M. Gottesman (1987) Biochem. J. 246, 731-735). Other characteristics shared by the guinea pig and mouse zymogens included proteolytic activity at pH 5.0, homologous N-terminal amino acid sequences, and immunological relatedness. It was thus concluded that acrosomal procathepsin L is the guinea pig analog of MEP. Acrosomal procathepsin L had a specific activity on benzyloxy-carbonyl-Phe-Arg-7-(4-methyl)coumarylamide (Z-Phe-Arg-NMec) of 30 mumol min-1 mg-1 enzyme at pH 3.2 and 37 degrees C. Relative to the assay substrate, rates on other fluorogenic substrates were 90% for Z-Phe-Cit-NMec, 63% for Z-Leu-Leu-Arg-NMec, 43% for D-Phe-Ser(Bzl)-Phe-Phe-Ala-Ala-p-aminobenzoate (a "specific" cathepsin D assay substrate), and 32% for Z-Val-Val-Arg-NMec. No action was detected on Z-Arg-Arg-NMec or Arg-NMec. Mature cathepsin L showed the same relative order of substrate specificity as its proenzyme form, but the absolute rates were about 5-fold greater. Additionally, the mature (single-chain) form of cathepsin L displayed Km and kcat values on Z-Phe-Arg-NMec that yielded an exceptionally high catalytic coefficient (11,600 s-1 mM-1) compared to values reported for two-chain forms of cathepsin L. Self-processing by acrosomal procathepsin L at pH 5.5 was totally inhibited by leupeptin, cystatin C, Ep-475, and Z-Phe-Phe-CHN2 at 1 microM levels. Gossypol (0.1 mM) gave 94% inhibition. Interestingly, dextran sulfate (100 micrograms ml-1) gave a 3.6-fold increase in the rate of self-processing seen at pH 5.5--a phenomenon of potential physiological relevance in view of the high-negative-charge density present within the hyaluronic acid-rich outer layer (cumulus oophorus) of the ovum.
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PMID:Purification and characterization of procathepsin L, a self-processing zymogen of guinea pig spermatozoa that acts on a cathepsin D assay substrate. 748 6

Proteolytic processing of neuropeptide precursors is required for production of active neurotransmitters and hormones. In this study, a chromaffin granule (CG) aspartic proteinase of 70 kDa was found to contribute to enkephalin precursor cleaving activity, as assayed with recombinant ([35S]Met) preproenkephalin. The 70-kDa CG aspartic proteinase was purified by concanavalin A-Sepharose, Sephacryl S-200, and pepstatin A agarose affinity chromatography. The proteinase showed optimal activity at pH 5.5. It was potently inhibited by pepstatin A, a selective aspartic proteinase inhibitor, but not by inhibitors of serine, cysteine, or metalloproteinases. Lack of inhibition by Val-D-Leu-Pro-Phe-Val-D-Leu--an inhibitor of pepsin, cathepsin D, and cathepsin E--distinguishes the CG aspartic proteinases from classical members of the aspartic proteinase family. The CG aspartic proteinase cleaved recombinant proenkephalin between the Lys172-Arg173 pair located at the COOH-terminus of (Met)enkephalin-Arg6-Gly7-Leu8, as assessed by peptide microsequencing. The importance of full-length prohormone as substrate was demonstrated by the enzyme's ability to hydrolyze 35S-labeled proenkephalin and proopiomelanocortin and its inability to cleave tri- and tetrapeptide substrates containing dibasic or monobasic cleavage sites. In this study, results provide evidence for the role of an aspartic proteinase in proenkephalin and prohormone processing.
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PMID:Characteristics of the chromaffin granule aspartic proteinase involved in proenkephalin processing. 756 75


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