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

Human placenta is surprisingly rich in post-proline dipeptidyl peptidase activity. Among various cell fractions, microsomes have the highest specific activity. A homogeneous enzyme preparation is obtained in a six-step purification procedure. The final preparation appears homogeneous upon dodecyl sulfate electrophoresis, but analytical isoelectric focussing reveals various active bands with isoelectric points in the range of pH 3-4. The enzyme is a glycoprotein containing about 30% carbohydrate. Treatment with neuraminidase lowers the isoelectric points but does not reduce the heterogeneity of the band pattern. The subunit molecular weight is 120000 as estimated by dodecyl sulfate electrophoresis, whereas Mr of the native enzyme is greater than 200000, as can be concluded from gel filtration experiments. The purified dipeptidyl peptidase cleaves various synthetic and natural peptides, including substance P, kentsin, casomorphin and a synthetic renin inhibitor. In general, the specificity of the placenta peptidase is similar to that of post-proline dipeptidyl peptidase from other sources. Phenylalanylprolyl-beta-naphthylamide (Km = 0.02 mM, V = 92 U/mg) is the best substrate among various synthetic peptide derivatives. Only peptides with a free N-terminal amino group and proline, hydroxyproline, or alanine in position 2 of the N-terminal sequence are cleaved. However, X-Pro-Pro-. . . structures, e.g. as in bradykinin, are not attacked. 1 mM bis-(4-nitrophenyl)phosphate or 1 mM diisopropylfluorophosphate completely inactivate the peptidase within 30 min at 30 degrees C (pH 8). The peptidase is also completely inhibited by 1 mM Zn2+ and by other heavy metals.
 ...
PMID:Isolation and characterization of dipeptidyl peptidase IV from human placenta. 675 24

A post-proline cleaving enzyme [post-proline endopeptidase: EC 3.4.21.26] was purified from lamb brain by a series of column chromatographies on DEAE-Sephadex, hydroxyapatite and Sephadex G-150. The purified enzyme appeared homogeneous on disc gel and sodium dodecyl sulfate (SDS) gel electrophoreses. The enzyme was most active at pH 7.0 with carbobenzoxy-Gly-Pro-beta-naphthylamide (Z-Gly-Pro-2-NNap) as a substrate and catalyzed the hydrolysis of oxytocin, vasopressin, thyrotropin releasing hormone (TRH), substance P, luteinizing hormone releasing hormone (LH-RH), and angiotensin at the carboxyl side of their proline residues, except for the Pro2-Lys3 bond in substance P. From the results of subsite mapping using synthetic peptides, five subsites, S3 to S2', for substrate interaction with the enzyme were deduced to be present, and high stereospecificity was observed at S2, S1, and S1'. The isoelectric point of the enzyme was at pH 4.9, and the molecular weights estimated by gel filtration and SDS gel electrophoresis were 74,000 and 77,000, respectively. The enzyme was markedly inhibited by diisopropylphosphoro fluoridate (DFP), carbobenzoxy-Gly-Pro-chloromethyl ketone (Z-Gly-Pro-CH2Cl), p-chloromercuribenzoate (PCMB), Hg2+, and Cu2+ ions. These enzymatic and protein chemical properties of post-proline cleaving enzyme from lamb brain closely resemble those of the lamb kidney enzyme, except for the molecular weight. In the present work, however, we decided that the molecular weight of the enzyme from lamb kidney was also 74,000, which is different from that reported previously (J. Biol. Chem. 251, 7593 (1976) but is in accord with the value of post-proline cleaving enzyme from lamb brain.
 ...
PMID:Post-proline cleaving enzyme from lamb brain. 702 30

Human proteoglycan was aggregated to an immobilized hyaluronan solid phase on a 96-well ELISA plate. This complex was then degraded by recombinant human stromelysin. The remaining proteoglycan fragments were detected using a monoclonal antibody probe directed against the chondroitin sulfate (CS) region of the core protein. Stromelysin degraded the aggregate in a time and dose dependent manner as reflected by the loss of the CS epitope. Assay sensitivity was 0.125 U/well with total loss of the CS epitope occurring at 4 U/well. o-phenanthroline (IC50 = 52 microM) and U24522 (IC50 = 9 microM) inhibited degradation, while phosphoramidon did not. Serine and cysteine protease inhibitors had no effect. A comparative analysis of this assay with a reference method, substance P assay, gave similar inhibitor profiles. The use of aggregated human proteoglycan (native conformation) as a substrate, may better reflect how stromelysin inhibitors behave in the presence of complex substrates such as cartilage matrix.
 ...
PMID:A stromelysin assay for the assessment of metalloprotease inhibitors on human aggregated proteoglycan. 750

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.
 ...
PMID:Purification and characterization of prolyl endopeptidase from rat skin. 750 52

In the present study, substance P (SP) was injected intraperitoneally (IP), and its effects on operant behavior were assessed in rats, which had been trained to bar press for food reward on a fixed-ratio (FR) 20 schedule. These effects were compared with IP injection of morphine sulfate, which had previously been shown to strongly suppress operant responding on FR schedules. The IP injection of SP resulted in a dose-related decrement in response rates. SP in a dose range of 250-500 micrograms/kg decreased operant responding, whereas SP in a dose range of 5-50 micrograms/kg did not influence response rates. The IP injection of morphine (10 mg/kg) markedly suppressed operant responding. However, in contrast to the rate-decreasing effects of SP, this suppression was not selective for the reinforced lever as responding on the nonreinforced lever, used as a control, was also decreased. Furthermore, both injection of 10 mg/kg morphine and SP in a dose range of 250-500 micrograms/kg was found to reduce food intake when the animals had free access to food subsequent to the operant conditioning session. The present results provide the first evidence that systemically administered neurokinin SP can affect operant responding for food reward. The suppressive effects on operant behavior and feeding obtained with systemic SP or morphine are discussed with respect to recent findings showing that both drugs can modulate mesolimbic dopamine activity after systemic drug injection.
 ...
PMID:Comparison of neurokinin substance P with morphine in effects on food-reinforced operant behavior and feeding. 751 95

The neuropeptide substance P acts, at micromolar concentrations, as a noncompetitive antagonist of nicotinic acetylcholine receptors (AChRs) of both neuronal and muscle subtypes. The mechanism of this inhibition has been shown to be most consistent with stabilization of a nonconducting desensitized state of the AChR, via binding to a site distinct from both the agonist site and the high affinity noncompetitive antagonist site. We have used a radioiodinated photoreactive analogue of substance P, containing the amino acid p-benzoyl-L-phenylalanine in place of the Phe8 residue of substance P, to identify the sites of interaction of substance P within the Torpedo california AChR. AChR-rich membrane suspensions were photolabeled in the absence or presence of the agonist carbamylcholine and/or nonradioactive substance P, and incorporation into AChR subunits was assessed by autoradiography after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the absence of agonist 125I incorporation was detected in each subunit and was insensitive to substance P, whereas in the presence of carbamylcholine there was a 2-fold increase in photoincorporation into the AChR delta subunit that was inhibited by the addition of an excess of substance P. The sites of specific photoincorporation in the delta subunit were initially mapped by use of Staphylococcus aureus V8 protease to a 14-kDa fragment extending from delta Ile-192 to Glu-280. Further fragmentation of this 14-kDa fragment with trypsin and S. aureus V8 protease established that the sites of specific incorporation were restricted to the region delta Ser-253 to Glu-280, which contains the membrane-spanning region 2 that is known to form the lining of the ion channel. These results establish that in the presence of agonist at least a part of the undecapeptide substance P binds within the ion channel in the desensitized state of the AChR, and it is likely that the binding of substance P to this site is responsible for the action of substance P as a noncompetitive AChR antagonist.
 ...
PMID:Agonist-induced photoincorporation of a p-benzoylphenylalanine derivative of substance P into membrane-spanning region 2 of the Torpedo nicotinic acetylcholine receptor delta subunit. 752 76

To better understand the structural basis of the biological activity of the neuropeptide substance P SP; (Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2), two-dimensional nmr spectroscopy experiments and simulated annealing calculations were used to investigate the conformation adopted in the presence of the membrane model system sodium dodecyl sulfate. It was determined that SP in the presence of SDS micelles undergoes a conformational equilibrium between an alpha- and a 3(10)-helix involving the midregion (Pro4-Gln5-Gln6-Phe7-Phe8) of the peptide. The C-terminus adopts an extended conformation while the N-terminus remains quite flexible. The conformation adopted by SP in the presence of SDS micelles yields a structure that is consistent with the model of a neurokinin-1 selective ligand proposed by Convert.
 ...
PMID:NMR and molecular modeling investigations of the neuropeptide substance P in the presence of 15 mM sodium dodecyl sulfate micelles. 753 57

The sensory neuropeptides substance P and calcitonin gene-related peptide have been implicated in the mediation of pulpal inflammation. A possible role in healing following injury has also been suggested (Byers et al., 1990). This possibility has been investigated by an examination of a direct effect of substance P and calcitonin gene-related peptide in vitro on fibroblast-like cells derived from human dental pulp. Cells were cultured for 48 hr in Dulbecco's modified Eagle medium plus 20% fetal calf serum and antibiotics. Substance P and calcitonin gene-related peptide were added in the range from 10(-12) to 10(-4) mol/L. Fibroblast growth factor was used as a positive control. Effects on cell proliferation were assessed by cell counts (daily for 6 days) and [3H]-thymidine uptake (24 hr after the addition of peptides). An effect on cellular functional activity was measured by [35S]-sulfate incorporation into glycosaminoglycans, in confluent cell cultures. Both substance P and calcitonin gene-related peptide showed concentration-dependent stimulation of cell proliferation. The maximum stimulation of approximately 40% was achieved at substance P and calcitonin gene-related peptide concentrations of 10(-6) mol/L, comparable with stimulation by fibroblast growth factor. By contrast, little increase in glycosaminoglycan synthesis by confluent cells could be detected. The direct effect on pulp cells is consistent with a role of the neuropeptides in pulp healing. This is exerted at the level of cell proliferation, rather than functional activity.
 ...
PMID:The effects of neuropeptides (calcitonin gene-related peptide and substance P) on cultured human pulp cells. 754 Jan 88

Sorting between the regulated and the constitutive secretory pathway in exocrine cells is thought to involve aggregation of regulated secretory proteins. This study demonstrates that, unlike endocrine secretory proteins, exocrine secretory proteins, including amylase, do not undergo homotypic aggregation under the conditions found in the sorting organelles. Also, unlike other exocrine proteins, amylase does not aggregate with chondroitin sulfate. Since amylase exhibits heterotypic aggregation, the role of protein concentration in amylase sorting was tested in AR42J cells. Secretion was stimulated with substance P and cholecystokinin from both untreated and dexamethasone-treated cells, with more efficient stimulation from dexamethasone-treated cells. These results indicate that amylase sorting is enhanced when its expression is stimulated by dexamethasone treatment.
 ...
PMID:Aggregation and concentration-dependent sorting of exocrine regulated secretory proteins. 757 29

The modulatory effect of spinal serotonin (5-HT)1 receptors on nociception was studied in mice. 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and buspirone, putative 5-HT1A agonists, m-trifluoromethylphenyl-piperazine (TFMPP) and 7-trifluoromethyl-4(4-methyl-1-piperazinyl)-pyrrolo(1,2-1a)quinoxaline (CGS 12066B), 5-HT1B agonists, and 5-carboxamidotryptamine (5-CT), a mixed 5-HT1A and 5HT1B agonist, were used. Intrathecal administration of 8-OH-DPAT, buspirone and 5-CT (1-12 nmol/mouse) significantly facilitated the tail-flick reflex, whereas TFMPP and CGS 12066B prolonged tail-flick latency. When administered i.t. after s.c. pretreatment (25 min) with morphine sulfate, 8-OH-DPAT, buspirone and 5-CT shifted the morphine sulfate dose-response curve 3- to 5-fold to the right. Spiperone, propranolol and pindolol (mixed 5-HT1A and 5-HT1B antagonists) effectively reversed both the tail-flick facilitation and the antagonistic effect on morphine sulfate-induced antinociception produced by 8-OH-DPAT and 5-CT. In addition, simultaneous i.t. administration of 8-OH-DPAT with substance P or N-methyl-D-aspartic acid decreased biting but increased scratching behavior, an effect which is also blocked by the 5-HT1 antagonists. These results confirm and extend other reports on the facilitory role of 5-HT1A receptor subtype on nociceptive responses and support the involvement of 5-HT1B receptor subtype in the antinociceptive action of serotonin.
 ...
PMID:Differential roles of 5-hydroxytryptamine1A and 5-hydroxytryptamine1B receptor subtypes in modulating spinal nociceptive transmission in mice. 768 14


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>