Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.15.1 (ACE)
 18,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mass spectrometry was used to verify portions of a proposed amino acid sequence of the bacteriophage P22 tail protein which had been inferred from the DNA base sequence. The exopeptidases dipeptidyl aminopeptidase I and IV and dipeptidyl carboxypeptidase were used to hydrolyse intact protein and fragments generated by cyanogen bromide treatment of the tail protein. After partial purification by high performance liquid chromatography, peptides were identified by gas chromatography/mass spectrometry and fast atom bombardment mass spectrometry. The results indicate that the initiation amino acid, N-formylmethionine, has been removed from the N-terminal of the protein and that the protein ends at the termination codon which is 667 amino acids from the N-terminal residue. Nine regions of the protein from 13 to 42 residues in length were verified. All of the sequences checked were in the same DNA reading frame and corresponded to the proposed sequence.
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PMID:Verification of the DNA predicted amino acid sequence of bacteriophage P22 tail protein by mass spectrometry. 293 Nov 29

The cellular relationships between angiotensin converting enzyme (ACE) (EC 3.4.14.1) and angiotensin-like immunoreactivity (AGLI) were examined in the subfornical organ (SFO). Brains from adult rats were fixed by vascular perfusion with 3.75% acrolein and 2% paraformaldehyde. The region containing the SFO was then sectioned on a vibrating microtome. Partially permeabilized sections were immunocytochemically labeled using the peroxidase-antiperoxidase (PAP) or combined PAP and immunogold methods. Goat antiserum to ACE was localized to both non-neuronal and neuronal cells within the SFO. Intense peroxidase immunoreactivity for ACE was associated with the ventricular and basal surface of ependymal cells, the luminal surface of the vascular endothelium, portions of glial membranes exposed to extracellular spaces, and membranous organelles within neuronal processes. Two antisera raised in rabbits against angiotensin II showed peroxidase immunoreactivity within the extracellular spaces and throughout the cytoplasm of numerous axon terminals and a few perikarya and dendrites in the SFO. Axon terminals and dendrites also showed aggregates of AGLI in smooth membranes and vesicles near the plasmalemma. Gold labeling for AGLI was evident in only 6% of the axon terminals and in a smaller number of dendrites containing peroxidase immunoreactivity for ACE. The low incidence of terminals containing both markers appeared to at least partially reflect limited penetration of the 10 nm gold particles. These results provide the first ultrastructural evidence that ACE is associated with the plasmalemma and membranous organelles strategically located for interaction with precursors of angiotensin II or other peptides within the cerebrospinal fluid, extracellular spaces and neurons of the SFO.
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PMID:Dual peroxidase and colloidal gold-labeling study of angiotensin converting enzyme and angiotensin-like immunoreactivity in the rat subfornical organ. 301 92

Cysteine proteinases are widely distributed among living organisms. According to the most recent classifications (Rawlings and Barrett, 1993, 1994), they can be subdivided on the basis of sequence homology into 14 or even 20 different families, the most important being the papain and the calpain families. The papain-like cysteine proteinases are the most abundant among the cysteine proteinases. The family consists of papain and related plant proteinases such as chymopapain, caricain, bromelain, actinidin, ficin, and aleurain, and the lysosomal cathepsins B, H, L, S, C and K. Most of these enzymes are relatively small proteins with Mr values in the range 20000-35000 (reviewed in Brocklehurst et al., 1987; Polgar, 1989; Rawlings and Barrett, 1994; Berti and Storer, 1995), with the exception of cathepsin C, which is an oligomeric enzyme with Mr approximately 200000 (Metrione et al., 1970; Dolenc et al., 1995). A number of cysteine proteinases are located within lysosomes. Four of them, cathepsins B, C, H and L, are ubiquitous in lysosomes of animals, whereas cathepsin S has a more restricted localisation (Barrett and Kirschke, 1981; Kirschke and Wiederanders, 1994). The enzymes, except cathepsin C, are endopeptidases (reviewed in Kirschke et al., 1995), although cathepsin B was found also to be a dipeptidyl carboxypeptidase (Aronson and Barrett, 1978) and cathepsin H also an aminopeptidase (Koga et al., 1992). Cathepsin C is a dipeptidyl aminopeptidase, but at higher pH it exhibits also dipeptidyl transferase activity (reviewed in Kirschke et al., 1995). Among the lysosomal cysteine proteinases, cathepsin L was found to be the most active in degradation of protein substrates, such as collagen, elastin and azocasein (Barrett and Kirschke, 1981; Maciewicz et al., 1987; Mason et al., 1989), arid cathepsin B the most abundant (Kirschke and Barrett, 1981). All the enzymes are optimally active at slightly acidic pH, although their pH optima for degradation of synthetic substrates vary from 5.5 for cathepsin L to 6.8 for cathepsin H (reviewed in Kirschke et al., 1995). Several other lysosomal cysteine proteinases, such as cathepsins N, T and K, are known, although their properties are less well characterised (reviewed in Kirschke et al., 1995). In particular cathepsin K has attracted recent interest (Bromme et al., 1996; Shi et al., 1995; Bossard et al., 1996; Drake et al., 1996) and was found to be expressed specifically in osteoclasts (Drake et al., 1996) with properties similar to cathepsin L (Bossard et al., 1996).
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PMID:Structural and functional aspects of papain-like cysteine proteinases and their protein inhibitors. 916 64

Chymase mediates a major alternative way of angiotensin II production from angiotensin I beside angiotensin converting enzyme in the final step of the renin-angiotensin system. This enzyme is also involved in other physio-pathological processes such as angiogenesis, atherosclerosis and inflammation. Several purification attempts of natural or recombinant chymase were reported in the literature. Most of these reports were not successful in obtaining the recombinant enzyme in a highly active form and in large quantity. In the present study, we describe a facile route for the purification of the human recombinant chymase. Chymase being produced as inactive prochymase, to be cathepsin C-activated, newly raised anti-chymase Ig were used to follow the purification. In order to complete the available tools for the search of chymase inhibitors, we developed and assessed a new 96-well plate based assay for the measurement of enzyme activity, as well as a low throughput, HPLC-based one. The assays used an original derivative of angiotensin I, or the native hormone. Chymase was produced in CHO cells and appropriately matured. The amount of enzyme obtained at the end of the process is compatible with the medium-throughput screening (up to 10,000 points per day), about 800 microg x L(-1) of culture medium with a specific activity of 6.16 mmol of angiotensin I cleaved per minute per mg of protein. All the biological and technical tools are now available for the discovery of new classes of chymase inhibitors.
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PMID:Development of new assays and improved procedures for the purification of recombinant human chymase. 1172 76

The Angiotensin I converting enzyme (ACE, EC 3.4.14.1, kininase II) and neutral endopeptidases (NEP, NEP 24.11) are mechanistically related metallopeptidases. They play a key role in the regulation of blood pressure, body fluid homeostasis and cell growth. Therefore, they are implicated in the pathogenesis of arterial hypertension, congestive heart failure, left ventricular remodeling after myocardial infarction and other cardiovascular diseases. Furthermore, since these two metallopeptidases possess some subsite and substrate similarities, as indicated by their interaction with certain mercaptoalkanoyl inhibitors, they are regarded as an important common target for pharmacological inhibition with a single drug. MDL 100240 is a pro-drug that, upon conversion to MDL 100173, acts as a potent dual inhibitor of ACE and NEP with a balanced activity on both enzymes. Only very limited pharmacokinetic studies with MDL 100240 have been published. These studies used a high pressure liquid chromatography method with UV absorbance detection to quantify the drug. According to the studies in dogs the terminal t(1/2) of MDL 100173 was 35.7 h. The area under the curve for total MDL 100173 was nearly 10-fold greater than the sum of the areas under the curve for MDL 100240 and for unconjugated MDL 100173. These results support the hypothesis that MDL 100240 is hydrolyzed in plasma to the active thiol, MDL 100173, which is rapidly conjugated with endogenous plasma thiols thus providing a pathway for elimination. Studies in vivo in experimental models of hypertension and congestive heart failure confirmed the vasodilatory and natriuretic effects of MDL, which appear to be independent of the degree of activation of the renin-angiotensin-aldosterone system. In addition, MDL 100240 showed an impressive effectiveness both in preventing and in regressing hypertension-induced vascular remodeling and cardiac hypertrophy. Accordingly, MDL 100240 is being developed for the treatment of cardiovascular diseases, including hypertension and congestive heart failure. If the promises of this novel therapeutic strategy are fulfilled, clinical trials are expected to demonstrate advantages of MDL 100240 over pure ACE inhibitors.
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PMID:Dual ACE and NEP inhibitors: a review of the pharmacological properties of MDL 100240. 1259 17

Chymase is an ACE (angiotensin-converting enzyme)-independent angiotensin II-forming enzyme whose expression is increased in the maternal vascular endothelium in preeclampsia. However, mechanisms underlying chymase activation in preeclampsia remain unclear. Cathepsin C is a key enzyme in the activation of several serine proteases including chymase. In this study, we determined whether increased cathepsin C expression/activity might be responsible for the upregulation of chymase expression in preeclampsia. Maternal vascular cathepsin C, chymase and ACE expression were examined through immunohistochemical staining of subcutaneous fat tissue sections of normal and preeclamptic pregnant women. The role of cathepsin C in endothelial chymase and ACE expression was determined in cells treated with cathepsin C. Consequences of chymase activation were then determined by measurement of angiotensin II production in cells treated with the ACE inhibitor captopril and the chymase inhibitor chymostatin, separately and in combination. Expression of both cathepsin C and chymase, but not ACE expression, was markedly increased in the maternal vascular endothelium in subjects with preeclampsia compared with normal pregnant controls. Exogenous cathepsin C induced a dose-dependent increase in expression of mature cathepsin C and chymase, but not ACE, in endothelial cells. Moreover, angiotensin II production was significantly inhibited in cells treated with captopril or chymostatin alone and was further inhibited in cells treated with both inhibitors. These results suggest that cathepsin C upregulation induces chymase activation and subsequently promotes angiotensin II generation in endothelial cells. These data also provide evidence of upregulation of the cathepsin C-chymase-angiotensin signaling axis in maternal vasculature in preeclampsia.
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PMID:Upregulation of cathepsin C expression contributes to endothelial chymase activation in preeclampsia. 2887 98