Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The prolyl endopeptidase from pig brain was purified to homogeneity according to SDS-gel electrophoresis and visualization with the silver staining procedure. The molecular weight of prolyl endopeptidase was estimated as 70 kDa, and the isoelectric point as 4.9. The molecular properties of prolyl endopeptidase from pig brain are therefore similar to those of prolyl endopeptidases from other mammalian tissues. Diisopropylfluorophosphate, diethylpyrocarbonate and p-chloromercuribenzoic acid are strong irreversible inhibitors of prolyl endopeptidase from pig brain. We showed that diisopropylfluorophosphate und diethylpyrocarbonate act as competitive inhibitors with respect to substrate. Therefore it is assumed that at least one serine and one histidine residue are located at the active site of this enzyme. This result supports the assumption that the prolyl endopeptidase from pig brain is a typical serine protease. Substance P, thyreoliberin, beta-casomorphin-5 and morphiceptin are hydrolysed by prolyl endopeptidase in vitro.
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PMID:Purification and characterization of prolyl endopeptidase from pig brain. 209 Jan 62

Neuronal and glial localization of brain peptidases was investigated by means of the kainic acid (KA) lesion technique. Activities of 6 different peptidases were measured in the rat caudate-putamen (CP) and substantia nigra (SN) 2, 7 and 21 days after unilateral intra-CP injection with 2.5 micrograms of KA. As an indicator of KA lesion in CP, substance P content in both CP and SN was also determined. In addition, activities of the same peptidases in the primary and secondary glial cell cultures of fetal rats were measured and compared to those in CP homogenate. After the KA injection, prolyl endopeptidase (Pro-EP) activity was decreased in the lesioned CP and, to a lesser extent, in the ipsilateral SN. The activity of angiotensin-converting enzyme (ACE) in the lesioned CP was decreased with a complex time course, whereas a slow and progressive reduction was observed in the SN. Alanyl and leucyl aminopeptidase (Ala-AP and Leu-AP respectively) activities gave only small changes after the lesion; Ala-AP was decreased and Leu-AP was increased in the lesioned CP, while both were decreased in the SN. Dipeptidyl aminopeptidase (DAP) and arginyl endopeptidase (Arg-EP) activities were increased 5-fold in the CP 7 days after the KA injection. Their increases paralleled that of beta-glucuronidase, the lysosomal marker enzyme. Cultured glial cells contained only a trace amount of ACE activity. Ala-AP and Pro-EP activities were considerably lower in the glial culture cells than in the CP homogenate. In contrast, DAP and Arg-EP as well as lysosomal marker enzymes showed much higher activity in the former than in the latter. These results suggest that (1) Ala-AP and Pro-EP have large neuronal components, (2) ACE is preferencially localized in neurons and (3) DAP and Arg-EP are associated with glial lysosomal function. It is, therefore, concluded that at least a part of the brain peptidases are differentially localized in neurons and glia, and may be involved in specific neuronal or glial function.
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PMID:Brain peptidases: their possible neuronal and glial localization. 608 24

We determined changes in prolyl endopeptidase activity in developing rat brain. A new and highly sensitive fluorogenic substrate, 7-(succinyl-Gly-Pro)-4-methylcoumarinamide, was used for determination of the enzyme activity. The enzyme activity per brain increased until 2 weeks of age, and then decreased during maturation. The enzyme was purified about 7800-fold from the brain of the rat at 2 or 3 weeks of age. The enzyme has a pH optimum of 5.8 to 6.5, and an approximate molecular weight of 70,000. The enzyme activity was completely inhibited by low concentrations of diisopropylfluorophosphate and partially inhibited by high concentrations of phenylmethanesulphonylfluoride, which are potent serine protease inhibitors. Moreover, thiolblocking agents and some heavy metals also have a strong effect on the activity. Bacitracin was found to be a potent inhibitor, with an IC50 value of 2.5 x 10(-6) M at 0.5 mM of the substrate. The enzyme was proved to hydrolyze the NH2-terminal tetrapeptide. Arg1-Pro2-Lys3-Pro4, from substance P to produce the heptapeptide, Gln5-Gln6-Phe7-Phe8-Gly9-Leu10-Met11-CONH2. The Km value of the hydrolysis of substance P was 1.0 mM. This enzyme may be related to the regulation of substance P in the brain, and to the development of neurones by forming the tetrapeptide because the tetrapeptide has almost the same effect as substance P on the neurite extension of neuroblastoma.
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PMID:Changes in prolyl endopeptidase during maturation of rat brain and hydrolysis of substance P by the purified enzyme. 616 Dec 26

Prolyl endopeptidase cleaves peptide bonds on the carboxyl side of proline residues within a peptide chain. The enzyme readily degrades a number of neuropeptides including substance P, neurotensin, thyrotropin-releasing hormone, and luteinizing hormone-releasing hormone. The finding that the enzyme is inhibited by benzyloxycarbonyl-prolyl-proline, with a Ki of 50 microM, prompted the synthesis of benzyloxycarbonyl-prolyl-prolinal as a potential transition state analog inhibitor. Rabbit brain prolyl endopeptidase was purified to homogeneity for these studies. The aldehyde was found to be a remarkably potent inhibitor of prolyl endopeptidase with a Ki of 14 nM. This Ki is more than 3000 times lower than that of the corresponding acid or alcohol. By analogy with other transition state inhibitors, it can be assumed that binding of the prolinal residue to the S1 subsite and the formation of a hemiacetal with the active serine of the enzyme greatly contribute to the potency of inhibition. The specificity of the inhibitor is indicated by the finding that a variety of proteases were not affected at concentrations 150 times greater than the Ki for prolyl endopeptidase. The data indicate that benzyloxycarbonyl-prolyl-prolinal is a specific and potent inhibitor of prolyl endopeptidase and that consequently it should be of value in in vivo studies on the physiological role of the enzyme.
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PMID:Inhibition of rabbit brain prolyl endopeptidase by n-benzyloxycarbonyl-prolyl-prolinal, a transition state aldehyde inhibitor. 634 24

Prolyl endopeptidase (E.C. 3.4.21.26) an enzyme previously called post proline cleaving enzyme, TRH-deamidase or kininase B, may play a role in neuropeptide metabolism. This enzyme, highly active in brain and other tissues, catabolizes proline-containing peptides such as substance P, neurotensin, luteinizing hormone-releasing hormone, thyrotropin releasing hormone, bradykinin and angiotensin II. The structure of beta-neo-endorphin suggests that this opioid peptide is formed by the action of prolyl endopeptidase on a precursor of higher molecular weight. Formation of two biologically active fragments of substance P also requires the action of this enzyme. This review summarizes the current knowledge of the biochemistry of this enzyme, and its potential significance for neuropeptide physiology and pharmacology.
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PMID:Prolyl endopeptidase. 635 55

A post-proline cleaving enzyme [prolyl endopeptidase, EC 3.4.21.26] was purified about 3,700-fold from an extract of bovine brain by a series of column chromatographies on DEAE-Sephadex, hydroxyapatite and PCMB-T-Sepharose, and gel filtration on Sephadex G-200 using N-carbobenzoxy-Gly-Pro-beta-naphthylamide (Z-Gly-Pro-2-NNap), thyrotropin releasing hormone (TRH) and oxytocin as substrates. The purified enzyme appeared homogeneous as judged by disc gel and SDS gel electrophoreses. The enzyme was most active at pH 7.5 and 7.2 with Z-Gly-Pro-2-NNap and TRH, respectively, and hydrolyzed peptide bonds involving Pro-X (X=amino acid, peptide, ester and amide) bonds of synthetic substrates, oxytocin, vasopressin, neurotensin, substance P, tuftsin, bradykinin, and insulin B chain. However, the enzyme was inert toward collagen, gelatin, and casein. The enzyme was completely inactivated by diisopropylphosphorofluoridate (DFP), Z-Gly-Pro-chloromethyl ketone and p-chloromercuribenzoate (PCMB), while it was not inhibited by phenylmethane sulfonylfluoride (PMSF) or metal chelators. Determination of the amino acid composition revealed that the enzyme contained 25 half-cystines. Modification of three cysteine residues of the enzyme by PCMB led to complete inactivation. The isoelectric point of the enzyme was 4.8, and the molecular weight was estimated to be 76,000 by ultracentrifugal analysis and 75,000-74,000 by both gel filtration and sodium dodecyl sulfate (SDS) gel electrophoresis, suggesting that the enzyme is present as a monomer. These results indicate that the post-proline cleaving enzyme from bovine brain is very similar to those previously purified from lamb brain and kidney in its enzymatic properties, substrate specificity and physicochemical properties, in sharp contrast with the results obtained by Tate, who reported that the bovine brain prolyl endopeptidase was inert toward oxytocin, vasopressin and bradykinin.
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PMID:Post-proline cleaving enzyme (prolyl endopeptidase) from bovine brain. 636 Oct 10

An enzyme with the specificity of a prolyl endopeptidase was purified approximately 329-fold from rat skin. The enzyme has a molecular weight of 70,000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and a pH optimum of 5.8 as checked with 7-(Succinyl-Gly-Pro)-4- methylcoumarinamide (Suc-Gly-Pro-MCA) as the substrate. The optimal temperature for the enzyme activity was 40 degrees C. The Km and Vmax values for Suc-Gly-Pro-MCA were 0.7 mM and 68 nmol/min per mg protein, respectively. The enzyme activity was markedly inhibited by diisopropyl fluorophosphate, p-chloromercuribenzoic acid, N-ethylmaleimide, Zn2+ and Cu2+, while it was partially inhibited by phenylmethanesulphonyl fluoride. The purified enzyme was shown to release the N-terminal tetrapeptide, Arg-Pro-Lys-Pro, from substance P producing the C-terminal heptapeptide, Gln-Gln-Phe-Phe-Gly-Met- CONH2. In the skin, this enzyme might be related to the inactivation of substance P.
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PMID:Purification and characterization of prolyl endopeptidase from rat skin. 750 52

A measuring method sensitive to prolyl endopeptidase (EC 3.4.21.26, PEP) activity using native peptides (Arg-vasopressin or substance P) as substrates was established. The investigation of three different derivatization reagents, which had been developed for an amino acid analysis, demonstrated that 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole (NBDF) was the most suitable for the detection of Arg-Gly-NH2, which was released from Arg-vasopressin by PEP. Arg-Gly-NH2 was reacted with NBDF at 65 degrees C for 5 min at pH 7.6 and the reaction mixture was analysed by HPLC on a reverse-phase column by monitoring the fluorescence intensity. The detection limit was 1 picomol per injection and the linear standard calibration curve could be constructed in the range of 1 to 100 picomol per injection with a 3.0% relative standard deviation. This sensitive detection method for peptide was applied to the measurement of PEP activity using Arg-vasopressin as a substrate and 1 x 10(-3) unit of PEP activity was detectable. This method was also applicable to the measurement of PEP activity using substance P as a substrate by detecting the derivative of its fragment peptide (Arg-Pro-Lys-Pro).
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PMID:A sensitive detection method for peptide using 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole and its application to measure prolyl endopeptidase activity. 753 49

The effects of a novel prolyl endopeptidase (PEP) inhibitor, (S)-2-[[(S)-2-(hydroxyacetyl)-1-pyrrolidinyl]carbonyl]-N-(phenylmethyl) - 1-pyrrolidinecarboxamide (JTP-4819), on the PEP activity in the brain and on the contents of substance P (SP)- and arginine-vasopressin (AVP)-like immunoreactivity (LI) in the cerebral cortex and hippocampus of young and aged rats were investigated using enzyme immunoassay. JTP-4819 exhibited a concentration-dependent in vitro inhibitory action on PEP activity in the brains of both young and aged rats, with IC50 values of approximately 0.7 and 0.8 nM, respectively. A single dose of JTP-4819 (3 mg/kg, p.o.) increased the SPLI content in the cerebral cortex but not the hippocampus of aged rats (23-24 months old). In addition, repeated administration of JTP-4819 (1 mg/kg, p.o., for 21 days) increased the SPLI content in the cerebral cortex and restored the SPLI content in the hippocampus, which had decreased with aging. In contrast, single (1 mg/kg, p.o.) and repeated (1 mg/kg, p.o., for 21 days) administration of JTP-4819 only tended to increase the AVPLI content of the hippocampus and cerebral cortex in aged rats, respectively. These results indicate that JTP-4819 increases the cerebral and hippocampal SPLI content in aged rats by inhibiting the action of PEP.
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PMID:Effect of a novel prolyl endopeptidase inhibitor, JTP-4819, on prolyl endopeptidase activity and substance P- and arginine-vasopressin-like immunoreactivity in the brains of aged rats. 754 Jun 63

JTP-4819 ((S)-2-[[(S)-2-(hydroxyacetyl)-1-pyrrolidinyl]carbonyl]-N- phenylmethyl)-1-pyrrolidinecarboxamide) is a potent (IC50: 0.83 +/- 0.09 nM in rat brain supernatant; 5.43 +/- 0.81 nM in Flavobacterium meningosepticum) and specific inhibitor of prolyl endopeptidase (PEP). JTP-4819 (3 mg/kg p.o.) exhibited a strong and durable ex vivo inhibitory effect on PEP in various regions of the rat brain. In addition, JTP-4819 inhibited the degradation of substance P, arginine-vasopressin, thyrotropin-releasing hormone, neurotensin, oxytocin, bradykinin, and angiotensin II by purified PEP with IC50 values of 9.6, 13.9, 10.7, 14.0, 4.5, 7.6 and 10.6 nM, respectively. In the one-trial passive avoidance test in rats with scopolamine-induced amnesia, JTP-4819 significantly prolonged the retention time when administered orally at doses of 1 and 3 mg/kg 1 hr before acquisition or at 3 and 10 mg/kg 1 hr before retention. In addition, coadministration of JTP-4819 and substance P, arginine-vasopressin or thyrotropin-releasing hormone (at doses at which each drug alone did not prolong the retention time) improved the retention time of rats with scopolamine-induced amnesia. Microdialysis studies demonstrated that JTP-4819 caused a significant increase in ACh release in the frontal cortex and hippocampus of young rats at oral doses of 1 and 3 mg/kg, as well as in both brain regions of aged rats at a dose of 3 mg/kg. These results indicate that JTP-4819 potentiates neuropeptide functions inhibiting PEP, that it activates cholinergic transmission and that it enhances learning and memory.
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PMID:JTP-4819: a novel prolyl endopeptidase inhibitor with potential as a cognitive enhancer. 756 10


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