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)

Procathepsin D is the intracellular aspartyl protease precursor of cathepsin D, a major lysosomal enzyme. Procathepsin D is rapidly processed inside the cell, and, thus, examination of its proteolyic activation and structure has been difficult. To study this proenzyme, a nonglycosylated form of the human fibroblast procathepsin D was expressed in Escherichia coli, refold in vitro, and purified by affinity chromatography on pepstatinyl agarose. Sequence analysis of the refolded, autoactivated enzyme allowed determination of the autoproteolytic cleavage site. The sequence surrounding this cleavage site between residues LeuP26 and IleP27 (in the "pro" region) resembled the first cleavage site found during activation of other aspartyl proteases. Thus, the autoactivated procathepsin D is analogous to the pepsin activation intermediate, which has been termed pseudopepsin. The enzymatic activity, thermal and pH stability, and fluorescence spectra of pseudocathepsin D were compared to mature, predominantly two-chain, cathepsin D isolated from human placenta. The results indicated that pseudocathepsin D and mature enzyme have a similar Km toward a peptide substrate and cleave a protein substrate at identical sites. Temperature stability of the recombinant enzyme was similar to that of the tissue-derived enzyme. However, the recombinant enzyme had increased stability at low pH when compared to the glycosylated tissue-derived two-chain cathepsin D. Fluorescence spectra of the recombinant and tissue-derived enzymes were identical. Thus, the absence of asparagine-linked oligosaccharides and the presence of the remaining segment of propeptide did not significantly alter the structural and enzymatic properties of the enzyme.
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PMID:Isolation and characterization of a stable activation intermediate of the lysosomal aspartyl protease cathepsin D. 173 61

The refined structures of two isomorphous pepsin/inhibitor complexes demonstrate that significant conformational changes take place upon ligand binding for a mammalian representative of the aspartic proteinase family. These differences can be attributed mostly to the concerted rigid body movements of two separate clusters of residues relative to a central core. One cluster in the amino domain comprises the flap, the adjacent beta strand (sheet IV) and helices, as well as the interconnecting loops. The other, larger cluster is in the carboxy end and corresponds approximately to the flexible subdomain described previously. Similar conformational changes are proposed to occur in renin and cathepsin D.
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PMID:Inhibitor binding induces structural changes in porcine pepsin. 181 63

A novel renin inhibitor, YM-21095 [2RS), (3S)-3-[N alpha-[1,4-dioxo-4-morpholino-2-(1-naphthylmethyl)-buthyl]-L- histidil-amino]-4-cyclohexyl-1-[(1-methyl-5-tetrazolyl)thio]-2-but anol), has been synthesized in our laboratories. The aim of this study was to evaluate the pharmacological properties of YM-21095 in in vitro and in vivo experiments. YM-21095 inhibited human renin with an IC50 value of 4.7 x 10(-10) mol/L. YM-21095 was also a potent inhibitor against squirrel monkey renin, but less effective against renins from dog, rabbit, and rat. The effect of YM-21095 is highly specific for renin, since it did not inhibit cathepsin D, pepsin, or angiotensin converting enzyme up to a concentration of 10(-4) mol/L. YM-21095 was resistant to proteolytic actions of the enzymes (pepsin, chymotrypsin, trypsin) and squirrel monkey tissue homogenates (liver, kidney, small intestine). Intravenous infusion of YM-21095 (0.1 to 100 micrograms/kg/min) decreased mean blood pressure and inhibited plasma renin activity in a dose-dependent manner with no effect on heart rate in anesthetized sodium-depleted and sodium-replete squirrel monkeys. The hypotensive effect of YM-21095 in sodium-depleted squirrel monkeys was about ten times as potent as that in sodium-replete squirrel monkeys. Oral administration of YM-21095 to conscious sodium-depleted squirrel monkeys produced dose-related decreases of systolic blood pressure. We conclude that YM-21095 is a potent and highly specific inhibitor of primate renin and produces a blood pressure lowering effect.
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PMID:Pharmacological properties of YM-21095, a potent and highly specific renin inhibitor. 181 49

Two propart peptides of aspartic proteinases, the propart peptide of chicken pepsin and human cathepsin D, respectively, were investigated from the point of view of their inhibitory activity for a set of aspartic proteinases. These peptides display a very broad inhibitory spectrum. The strongest inhibition was observed for pepsin A-like proteinases where propart peptides can be used as titrants of active enzymes.
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PMID:Inhibition of aspartic proteinases by propart peptides of human procathepsin D and chicken pepsinogen. 187 25

Pregnancy in cattle and sheep can be diagnosed by the presence of a conceptus-derived antigen in maternal serum that is secreted by trophoblast and placental tissue primarily as an acidic component of Mr 67,000. Molecular cloning of its cDNA reveals that the antigen belongs to the aspartic proteinase family and has greater than 50% amino acid sequence identity to pepsin, cathepsin D, and cathepsin E. The inferred sequences of the ovine and bovine polypeptides show approximately 73% identity to each other. Critical amino acid substitutions at the active site regions suggest that both proteins are enzymatically inactive. The antigen is a product of trophoblast binucleate cells that invade maternal endometrium at implantation sites.
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PMID:Identification of the major pregnancy-specific antigens of cattle and sheep as inactive members of the aspartic proteinase family. 194 44

A series of renin inhibitors containing ester side chains at the P2 subsite are potent inhibitors of primate renin. Derivatives containing the diol isostere (ACDMH) at P1-P1' were the most potent inhibitors. Moderate selectivity for renin was observed relative to the closely related aspartic proteinase cathepsin D. The prototype compound, 4 (PD 132002), inhibited pepsin only weakly. In both high-renin normotensive and high-renin renal hypertensive monkeys, 4 produced substantial reductions in blood pressure after oral administration of 30 mg/kg. The maximum drop in blood pressure observed (24 +/- 4 mmHg) in the renal hypertensive monkey model was comparable to the drop produced by an intravenous infusion of saralasin at a maximally effective dose. Both the magnitude and duration of the oral antihypertensive effect of 4 is greater than that produced by enalkiren, CGP-38560, or CP-80794 by direct comparison in the same hypertensive monkey model. The malonate ester derivatives were prepared as ca. 65:35 mixtures of epimers. The kinetics of epimerization of 4 were investigated in detail, and it was shown to equilibrate rapidly at physiological pH (t1/2 less than 2 min). Fractional crystallization was employed to obtain the individual diastereomers in greater than 98% purity, which were indistinguishable in terms of their activity in vitro or in vivo, presumably due to rapid epimerization under the testing conditions.
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PMID:Renin inhibitors containing esters at the P2-position. Oral activity in a derivative of methyl aminomalonate. 206 66

A novel series of renin inhibitors based on the Phe8-His9-Leu10-Val11 substructure of renin's natural substrate, angiotensinogen, is reported. These inhibitors retain the Phe8-His9 portion of the native substructure and employ novel phosphostatine Leu10-Val11 replacements (LVRs). The phosphostatine LVRs were prepared by condensing a dialkyl phosphonate ester stabilized anion with either N-t-Boc-amino aldehydes or N-tritylamino aldehydes (derived from the corresponding amino acid). Structure-activity relationships at the Leu10 side chain revealed that the LVR derived from L-cyclohexylalanine provided a 130-fold boost in potency over the LVR derived from L-leucine. The dialkyl ester moiety was varied and a loss in potency was incurred when the alkyl ester was chain extended or alpha-branched; dimethyl esters provided optimum potency. The phosphonate moiety was replaced by a half-acid half-ester phosphonate and dimethylphosphinate; both replacements lead to a loss in potency. The more potent inhibitors (IC50 = 20-50 nM) were found to be selective inhibitors for renin over porcine pepsin and bovine cathepsin D (little or no inhibition was observed at 10(-5) M).
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PMID:New inhibitors of renin that contain novel phosphostatine Leu-Val replacements. 210 96

Our attempts to synthesize a potent inhibitor of rat renin have resulted in the discovery of CGP 44 099 A, a potent inhibitor of plasma renin from all subprimate species tested so far [IC50 (in nM): dog, 0.007; rabbit, 0.033; guinea pig, 0.34; mouse, 0.4; cat, 0.57; and rat, 1.3]. This compound is also a potent inhibitor of primate renins [IC50 (in nM): human, 0.3; and marmoset, 1.4]. It is less potent against other aspartic proteinases [IC50 (in nM): porcine pepsin, 26; and bovine cathepsin D, 230). CGP 44 099 A exhibited a competitive mode of inhibition against human renin (Ki, 0.12 nM). During i.v. infusion of CGP 44 099 A in sodium-depleted normotensive rats (0.1 mg/kg/min) blood pressure (BP) was lowered by about 25 mm Hg. Plasma renin activity, angiotensin I and angiotensin II were almost completely suppressed. The converting enzyme inhibitor enalaprilat (1 mg/kg i.v.) also lowered BP by about 25 mm Hg. No further fall in BP occurred when CGP 44 099 A (0.1 mg/kg/min) was infused after pretreatment with enalaprilat (1 mg/kg i.v.) and CGP 44 099 A did not lower BP when infused in bilaterally nephrectomized rats. These results indicate that the hypotensive response induced by CGP 44 099 A in sodium-depleted rats is specifically due to the renin inhibition. Compounds such as CGP 44 099 may therefore be useful for comparing the effects of renin inhibition in different species and for studying the role of renin in various models of cardiovascular disease in nonprimate species.
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PMID:Evaluation of a potent inhibitor of subprimate and primate renins. 211 Sep 74

A newly synthesized orally active renin inhibitor, N-morpholinoacetyl-(1-naphthyl)-L-alanyl-(4-thiazolyl)-L-alanyl (3S,4S)-4-amino-3-hydroxy-5-cyclohexylpentanoyl-n-hexylamide (ES-8891), was found to be a highly potent competitive inhibitor of human renin with an inhibition constant of 1.1 nM. This inhibitor was also active against monkey renin, although there was less inhibition of renin in pig, rabbit, and rat. ES-8891 did not inhibit cathepsin D, pepsin, trypsin, chymotrypsin, angiotensin converting enzyme, and urinary kallikrein at a concentration of 10(-5) M. A single oral administration of ES-8891 (10 or 30 mg/kg) to conscious, sodium-depleted marmosets caused a dose-related decrease in plasma renin activity and blood pressure. ES-8891 (30 mg/kg) produced an 80% inhibition of plasma renin activity, which lasted for more than 6 hours. Kidney renin messenger RNA was not significantly changed 6 hours after oral administration of ES-8891 (30 mg/kg). A single oral administration of 240 mg ES-8891 to healthy human volunteers (n = 6) produced a significant inhibition of plasma renin activity (75% inhibition at 0.5 and 1 hour, 50% inhibition at 2 hours) with a good correlation of plasma levels of ES-8891. There were no significant changes in blood pressure or heart rate, and no adverse effects were observed. These results suggest that ES-8891 is an orally active human renin inhibitor that may be clinically useful.
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PMID:ES-8891, an orally active inhibitor of human renin. 211 12

1. Three pepsins were purified from the gastric mucosa of Atlantic cod (Gadus morhua). 2. The enzymes, called Pepsin I and Pepsin IIa and b, had isoelectric points 6.9, 4.0 and 4.1, respectively, and digested hemoglobin at a maximal rate at a pH of approximately 3. 3. They resembled bovine cathepsin D in being unable to digest the mammalian pepsin substrate N-acetyl-L-phenylalanyl-3,5-diiodo-L-tyrosine. 4. Specificity constants (kcat/Km) for the cod pepsins were lower than for porcine pepsin, and they expressed higher substrate affinity and physiological efficiency at pH 3.5 than at pH 2. 5. The cod pepsins are glycoproteins, and their amino acid composition resembles that of porcine cathepsin D more than that of porcine pepsin. 6. The N-terminal sequence of Atlantic cod pepsins is substantially different from that of porcine pepsin. This indicates a significant evolutionary gap between fish and mammalian pepsins.
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PMID:Catalytic properties and chemical composition of pepsins from Atlantic cod (Gadus morhua). 211 46


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