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
Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Spantide (D-Arg1-Pro2-Lys3-Pro4-Gln5-Gln6-D-Trp7-Phe8-D-Trp9-++ +Leu10-Leu11-
NH2
) was introduced as a
tachykinin
antagonist in 1984 and has served as a starting point in the design of new antagonists that have proven to be more effective and have exhibited no neurological side effects. The most remarkable and unpredictable structural change that significantly increased potency was deletion of a methylene group by changing Gln6 to Asn6. On the basis that D-Arg1 and Lys3 of spantide contribute to neurological side effects, many new designs led to D-Lys(Nic)1-Pro2-Pal(3)3-Pro4-D-Phe(Cl2)5-Asn6-D-Trp7-Phe8-D-Trp9- Leu10-Nle11-
NH2
[spantide II, where D-Lys(Nic) is N epsilon-nicotinoyllysine, Pal(3) is 3-(3-pyridyl)alanine, D-Phe(Cl2) is 3,4-dichloro-D-phenylalanine, and Nle is norleucine], which is a potent antagonist without neurotoxicity. Spantide II, an undecapeptide, has a total of seven substitutions in the sequence of
substance P
, consisting of two natural L amino acids, and one unnatural L amino acid, and four unnatural D amino acids. The pi- and sigma-bond amino acid substituents of
substance P
and spantide II are compared toward a future understanding of the essential substituents for mechanism and inhibition binding. Spantide II has five pi-bond and six sigma-bond amino acid moieties, and
substance P
has two pi-bond and nine sigma-bond moieties.
...
PMID:Spantide II, an effective tachykinin antagonist having high potency and negligible neurotoxicity. 169 80
We discovered an enzyme in human platelets that deamidates
substance P
and other tachykinins. Because an amidated carboxyl terminus is important for biological activity, we purified and characterized this deamidase. The enzyme, released from human platelets by thrombin, was purified to homogeneity by ammonium sulfate precipitation, followed by chromatography on an octyl-Sepharose column and chromatofocusing on PBE 94. The purified enzyme exhibits esterase, peptidase, and deamidase activities. The peptidase activity (with furylacryloyl-Phe-Phe) is optimal at pH 5.0 while the esterase (benzoyl-tyrosine ethyl ester) and deamidase (D-Ala2-Leu5-enkephalinamide) activities are optimal at pH 7.0. With biologically important peptides, the enzyme acts both as a deamidase (
substance P
,
neurokinin A
, and eledoisin) and a carboxy-peptidase (with bradykinin, angiotensin I,
substance P
-free acid, oxytocin-free acid) at neutrality, although the carboxypeptidase action is faster at pH 5.5. Enkephalins, released upon deamidation of enkephalinamides, were not cleaved. Gly9-
NH2
of oxytocin was released without deamidation. Peptides with a penultimate Arg residue were not hydrolyzed. Some properties of the deamidase are similar to those reported for cathepsin A. The deamidase is inhibited by diisopropylfluorophosphate, inhibitors of chymotrypsin-type enzymes, and mercury compounds while other inhibitors of catheptic enzymes, trypsin-like enzymes, and metalloproteases were ineffective. In gel filtration, the native enzyme has an Mr = 94,000 while in non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis the Mr = 52,000 indicating it exists as a dimer. After reduction, deamidase dissociates into two chains of Mr = 33,000 and 21,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. [3H]diisopropylfluorophosphate labeled the active site serine in the Mr = 33,000 chain. The first 25 amino acids of both chains were sequenced. They are identical with the sequences of the two chains of lysosomal "protective protein" which, in turn, has sequence similarity to the KEX1 gene product and carboxypeptidase Y of yeast. This protective protein complexes with beta-galactosidase and neuraminidase in lysosomes and is vitally important in maintaining their activity and stability. A defect in this protein is the cause of galactosialidosis, a severe genetic disorder. The ability of physiological stimuli (e.g. thrombin or collagen) to release the deamidase from platelets indicates that it may also be involved in the local metabolism of bioactive peptides.
...
PMID:A peptidase in human platelets that deamidates tachykinins. Probable identity with the lysosomal "protective protein". 169 76
1. We have used pharmacologic, immunologic, and biochemical techniques to examine the role of neurochemicals in modulating the myogenic heart of the snail, Lymnaea. 2. 5-HT [high-pressure liquid chromatography (HPLC) and immunocytochemistry], dopamine (HPLC), FMRFamide-related peptides (radioimmunoassay and immunocytochemistry) and
substance P
-related peptides (immunocytochemistry) were shown to be localized within heart tissue. 3. The pharmacologic actions of these substances on the auricle from an isolated heart preparation were examined together with other putative modulators, acetylcholine (ACh), small cardioactive peptides A and B (SCPA and SCPB), [Arg]8vasotocin (AVT), and Lymnaea native FMRFamide-related peptides [Phe-Met-Arg-Phe-
NH2
(FMRFamide), Ser-Asp-Pro-Phe-Leu-Arg-Phe-
NH2
(SDPFLRFamide) and Gly-Asp-Pro-Phe-Leu-Arg-Phe-
NH2
(GDPFLRFamide)]. 4. The response to each substance could be distinguished by different effect on beat rate, amplitude, and diastolic tonus, as well as by the duration of responses to standard 1-min applications. ACh was inhibitory at low concentrations (threshold less than 10(-10) M) but excitatory at high concentrations (10(-6) M). AVT was alone in producing no dose-dependent response. At high concentrations (10(-4) M), AVT caused a massive tonic contraction and cessation of auricle beat. All other substances examined were excitatory. 5. Antagonists to 5-HT (cinanserin), dopamine (ergonovine), and ACh (alpha-bungarotoxin) were identified. 6. ACh, 5-HT, dopamine, and FMRFamide-related peptides all acted on the auricle at low concentrations, and the rapid onset and short duration of their excitatory effects (ACh inhibitory at low concentrations) suggested that they may have roles as neurotransmitters. SCPA and SCPB were also potent (threshold less than 10(-10) M) but produced long-duration responses suggesting a modulatory or hormonal role.
...
PMID:Pharmacology of the myogenic heart of the pond snail Lymnaea stagnalis. 169 38
Substance P
(SP) is one of the endogenous
tachykinin
peptides implicated in neurogenic inflammation and may be critically involved in diseases as diverse as asthma, arthritis and inflammatory bowel disease. The current study was initiated to identify a rich source of SP receptor that would be amenable for studying the regulatory mechanism of the receptor. By using a radioligand receptor binding technique, sheep ileal smooth muscle membranes showed a much higher density of [3H]SP specific binding than other non-neural rat or sheep tissues and organs surveyed. Of the protease inhibitors tested, only phosphoramidon, a specific and potent enkephalinase inhibitor, prevented the degradation of [3H]SP and enhanced [3H]SP binding to the membrane. [3H]SP binding to the specific binding sites in the membranes was time-dependent and reached a steady state after 60 min at 22 degrees C in 25 mM Tris.
NH3
(pH 7.4). Calcium and magnesium ions enhanced [3H]SP specific binding. Saturation binding studies showed that the dissociation constant (KD) and the density of maximum binding sites for [3H]SP specific binding were 0.54 nM and 83 fmol/mg of protein, respectively. The specificity of the [3H]SP labeled sites was SP greater than (4-11) SP greater than eledoisin greater than spantide greater than neurokinin-A greater than D-Pro2D-Phe7D-Trp9-SP. Neurokinin-B and senktide showed no inhibition of [3H]SP binding.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Identification and characterization of the substance P receptor in sheep intestinal smooth muscle membranes. 169 67
The effects of the
tachykinin
antagonist Spantide II (D-Nic-Lys1,3-Pal3,D-Cl2Phe5,Asn6,D-Trp7,9,Nl e11)-
substance P
(SP) and the vasoactive intestinal peptide (VIP) antagonist (Ac-Tyr1,D-Phe2)-GRF(1-29)-
NH2
on the excitability of the spinal nociceptive flexor reflex to intrathecally (i.t.) applied SP and VIP, respectively, as well as the facilitation evoked by activation of cutaneous C-afferent was examined. Both antagonists blocked the effects of the respective neuropeptides in rats with both intact and sectioned sciatic nerves. Spantide II antagonised C-afferent induced reflex facilitation in rats with intact nerves, but the degree of antagonism declined after axotomy. In contrast, the VIP antagonist did not block C-afferent induced facilitation in rats with intact nerves, but did so after axotomy. The results indicate that the role of tachykinins in mediating C-afferent-induced reflex facilitation is taken over by VIP after axotomy.
...
PMID:Plasticity of the peptidergic mediation of spinal reflex facilitation after peripheral nerve section in the rat. 170 Aug 43
The ability to assess the importance of secretin in various physiological processes is limited by the lack of specific potent antagonists. Recently, reduced peptide bond (psi) analogues of bombesin or
substance P
in which the -CONH- bond is replaced by -CH2NH- are reported to be receptor antagonists. To attempt to develop a new class of secretin receptor antagonists, we have adopted a similar strategy with secretin and sequentially altered the eight
NH2
-terminal peptide bonds, the biological active portion of secretin. In guinea pig pancreatic acini, secretin caused a 75-fold increase in cyclic AMP (cAMP). Secretin inhibited 125I-secretin binding with a half-maximal effect at 7 nM. Each of the psi analogues inhibited 125I-secretin binding. [psi 4,5]Secretin was the most potent, causing the half-maximal inhibition at 4 microM, and was 2-fold more potent than the [psi 1,2]secretin; 7-fold more than [psi 3,4]secretin, [psi 5,6]secretin, and [psi 8,9]secretin; 9-fold more than [psi 7,8]secretin; 13-fold more potent [psi 6,7]secretin, and 17-fold more than [psi 2,3]secretin. Secretin caused a half-maximal increase in cAMP at 1 nM. At concentrations up to 10 microM, [psi 2,3]secretin, [psi 4,5]secretin, and [psi 8,9]secretin did not alter cAMP whereas [psi 1,2]secretin and [psi 6,7]secretin caused a detectable increase in cAMP at 10 nM, [psi 7,8]secretin at 300 nM, [psi 5,6]secretin at 1 microM, and [psi 3,4]secretin at 10 microM. The [psi 4,5], [psi 2,3], and [psi 8,9] analogues of secretin each inhibited 1 nM secretin-stimulated cAMP as well as [psi 3,4]secretin, which functioned as a partial agonist. [psi 4,5]Secretin was the most potent, causing half-maximal inhibition at 3 microM whereas [psi 8,9]secretin was 6-fold less potent, and [psi 2,3]secretin and [psi 3,4]secretin were 17-fold less potent. [psi 4,5]Secretin inhibited secretin-stimulated cAMP and binding of 125I-secretin in a competitive manner. [psi 4,5]Secretin did not interact with cholecystokinin, bombesin, calcitonin gene-related peptide, or cholinergic receptors but did interact with receptors for vasoactive intestinal peptide, causing half-maximal inhibition at 72 microM and thus had a 18-fold higher affinity for secretin than vasoactive intestinal peptide receptors. These results indicate that reduced peptide bond analogues of the
NH2
terminus of secretin represent a new class of secretin receptor antagonists. It is likely that in the future even more potent members of this class can be developed which may be useful to investigate the role of secretin in various physiological processes.
...
PMID:Reduced peptide bond pseudopeptide analogues of secretin. A new class of secretin receptor antagonists. 170 23
Two undecapeptide
substance P
(SP) analogues, Spantide I and Spantide II, were tested for their capacity to block the contractile effect of SP on the guinea pig isolated taenia coli and the contractile effect of electrical stimulation of the rabbit isolated (and atropinized) iris sphincter, and for their capacity to mobilize histamine from rat isolated peritoneal mast cells. Spantide I and Spantide II have one feature in common, namely D-tryptophan in positions 7 and 9. Spantide I: D-Arg, Pro2, Lys3, Pro4, Gln5, Gln6, D-Trp7, Phe8, D-Trp9, Leu10, Leu11-
NH2
. Spantide II: D-NicLys1, Pro2, 3-Pal3, Pro4, D-Cl2Phe5, Asn6, D-Trp7, Phe8, D-Trp9, Leu10, Nle11-
NH2
. Both Spantide I and II were found to be competitive antagonists to SP on the taenia coli and to be capable of blocking the electrically induced non-cholinergic contraction of the iris sphincter. Spantide II had higher pA2 value (taenia coli) than Spantide I, 7.7 versus 7.0, and higher pIC50 value (blockade of
tachykinin
-mediated neurotransmission in iris sphincter), 6.0 versus 5.1. Both Spantide I and II mobilized histamine from rat peritoneal mast cells but Spantide II was less effective. Spantide I and II were tested for antagonistic specificity. Both blocked contractions of the taenia induced by SP and
neurokinin A
. In the concentration used, Spantide II in addition blocked the response to neurokinin B. The contractions induced by carbachol, 5-hydroxytryptamine, histamine and prostaglandins (F2 alpha and E1) were not affected; the contractile response to bombesin was inhibited by Spantide I but not by Spantide II.
...
PMID:Spantide II, a novel tachykinin antagonist having high potency and low histamine-releasing effect. 170 95
The substituted glucopyranose ring structure 2-hydroxypropyl-beta-cyclodextrin (CDEX) increases the solubility of molecules by inclusion of the agent in the lipophilic interior of the ring. This property is of particular use for the administration of molecules by the intracerebral (ICV) or intrathecal (IT) routes. In concentrations up to 40% w/v (isotonic), this agent (10 microliters) effect upon nociceptive or motor function after IT injection or on EEG and general behavior after ICV injection in rats. Using 20% CDEX, there is no change in the ED50 as compared to saline on the hot plate (HP) after IT injection of morphine, D-Ala2-D-Leu5 enkephalin or Tyr-Aib-Gly-gPhe-mAib-
NH2
, (Aib: alpha-aminoisobutyric acid) although there is an increase in their respective durations of effect. Cyclic peptide opioids: Tyr-c[D-A2bu-Gly-D-beta Nal(1)-D-Leu] (A2bu: alpha, gamma-diaminobutyric acid; beta-Nal(1): beta-naphthylalanine(1)) or Tyr-c[DA2bu-Gly-beta Nal(1)-D-Leu] are insoluble in saline but are readily dissolved in CDEX, and display a naloxone-sensitive antinociception following spinal administration. In other studies, saline insoluble capsaicin is administered in 25% dimethylsulfoxide (DMSO) or 20% CDEX (15 microliters; 5 mg/ml) which result in a significant reduction in the spinal levels of
substance P
and calcitonin gene related peptide and an increase in the HP latency. DMSO alone, but not CDEX alone, reduces the levels of the two peptides. These data emphasize the utility of complexation with CDEX for intracerebral drug delivery and compatibility with brain and spinal tissue.
...
PMID:The utility of 2-hydroxypropyl-beta-cyclodextrin as a vehicle for the intracerebral and intrathecal administration of drugs. 170 20
The IgA producing murine B lymphoma, CH12.LX.C4.4F10 (4F10) and the IgM producing murine lymphoma, CH12.LX.C4.5F5 (5F5) were found to express substantial numbers of
substance P
(SP) receptors having dissociation constants equal to 0.69 nM. Binding of SP by these B lymphoma cells was via the
tachykinin
-specific C-terminus sequence, Phe-X-Gly-Leu-Met-
NH2
, because SP, SP antagonist (D-Pro2-D-Phe7-D-Trp9-SP), eledoisin, and
substance K
could effectively inhibit radiolabeled SP binding, whereas the SP N-terminus fragment, SP (1-4), could not. The functionality of these receptors could be demonstrated by the ability of subnanomolar concentrations of SP to induce Ig secretion in a dose-dependent fashion. However, the presence of a second stimulus in these cultures was required to obtain maximal increases. IgA secretion by 4F10 cells was elevated only 25 to 37%, and IgM secretion by 5F5 cells was not significantly increased in cultures in which nanomolar concentrations of SP were present. Conversely, coculturing 5F5 cells with a suboptimal concentration of LPS (50 ng/ml) and 10(-10)M SP resulted in an approximate threefold increase in supernatant IgM when compared to control cultures stimulated with LPS alone. While not as dramatic, 10(-10) M SP also enhanced IgA secretion of LPS-stimulated 4F10 cells by approximately 45%. This enhancement of Ig secretion was SP-specific, as evidenced by the ability of 1000-fold excess of SP antagonist to block SP-induced, but not LPS-induced, Ig production. Clearly, SP could act synergistically with LPS to enhance Ig secretion; therefore, we questioned whether this augmentation was also reflected at the level of H chain mRNA expression. 10(-9)M SP induced modest increases (50 to 60%) in mu-chain mRNA expression by LPS-stimulated 5F5 cells when compared with cells stimulated with LPS alone. The 4F10 cells did not display this magnitude of difference for alpha-chain mRNA expression. Thus, although SP-induced increases of mu-chain mRNA by 5F5 cells may contribute to the increased Ig secretion observed by these LPS-activated lymphocytes, it is unlikely that increased mRNA expression can totally account for the threefold increases in secretion that were observed.
...
PMID:Substance P acts directly upon cloned B lymphoma cells to enhance IgA and IgM production. 170 87
A new hexapeptide analog of
Substance P
, containing a C-terminal thioamide group in the molecule [( Glp6, Mett11]SP6-11) was synthesized: Glp-Phe-Phe-Gly-Leu-Mett-
NH2
. Conversion to thioamide was accomplished from tert-butoxycarbonyl-L-methionine amide (Boc-Met-
NH2
) using Lawesson's Reagent. Its contracting activity on isolated guinea-pig ileum was considerably lower than that of [Glp6]SP6-11.
...
PMID:Synthesis and some biological properties of the hexapeptide analog of substance P with a C-terminal thioamide group. 171 85
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>