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)

We have developed a specific radioimmunoassay for "cerebellin", a 16-amino acid peptide recently isolated from rat cerebellum. In both rat and guinea-pig, cerebellin-like immunoreactivity was highest in the cerebellum but was also present in high concentrations elsewhere in the central nervous system, especially in the hypothalamus. In both species, cerebellin-like immunoreactivity was found in other organs (heart, kidney and stomach) and at lower concentrations in the gastrointestinal tract. In the brain of both species, cerebellin-like immunoreactivity consisted of a single molecular form with an elution position on gel filtration and high-performance liquid chromatography identical to that of synthetic rat cerebellin. However, peripheral tissue contained an additional immunoreactive peak of higher molecular weight. Cerebellin was concentrated in synaptosomal preparations of rat brain, and its subcellular distribution pattern in rat brain was identical to that of two other known synaptosomal peptides, vasoactive intestinal polypeptide and substance P. Studies with superfused cerebellar synaptosomes and slices of rat cerebellum and hypothalamus demonstrated calcium-dependent cerebellin release when stimulated by high potassium concentrations as well as the addition of the calcium ionophore A23187. Cerebellin has therefore a widespread distribution and fulfils two criteria for a neurotransmitter, in that it is found in brain synaptosomes and shows calcium dependent, depolarization-induced release from nervous tissues and isolated nerve endings. It may, therefore, be a component of a novel neurotransmitter system.
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PMID:Cerebellin-like peptide: tissue distribution in rat and guinea-pig and its release from rat cerebellum, hypothalamus and cerebellar synaptosomes in vitro. 339 60

In vitro, prolyl oligopeptidase (POP) cleaves proline-containing bioactive peptides such as substance P, gonadotropin-releasing hormone, thyrotropin-releasing hormone, arginine-vasopressin, and neurotensin. Based on specific in vivo inhibition, POP has been suggested to be involved in cognitive and psychiatric processes but the identity of its physiological substrates has remained inconclusive. We have combined (a) sample snap-freezing and boiling buffer extraction, to limit protein degradation and reduce sample complexity; (b) pH two-dimensional liquid reverse-phase chromatography to enhance resolution; and (c) iTRAQ isobaric labeling to identify the rat brain peptides whose levels were differentially changed due to in vivo POP inhibition. In the hypothalamus, all the substrates found were part of precursors of secreted peptides such as copeptin, PACAP-related peptide, somatostatin, and proSAAS derived peptides, while in the cerebellum the peptides were derived from carcinoma-amplified sequence 1 homolog and calmodulin. In the striatum, somatostatin precursor derived peptide, fragments from E3-SUMO protein ligase RanBP2, and the subunit 5A of cytochrome c oxidase were increased. When analyzing the peptides that were significantly reduced by POP inhibition we found fragments from large protein complexes but, exclusively in the cerebellum, bioactive peptides such as cerebellin and fibrinopeptides A and B were detected.
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PMID:Combination of snap freezing, differential pH two-dimensional reverse-phase high-performance liquid chromatography, and iTRAQ technology for the peptidomic analysis of the effect of prolyl oligopeptidase inhibition in the rat brain. 1953 95