UNIPROT:P01350 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UNIPROT:P01350 (gastrin)
9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sulfakinins constitute a family of real and putative peptide sequences characterized from the cockroach Leucophaea maderae (leucosulfakinin subfamily) and fruitfly Drosophila melanogaster (drosulfakinin subfamily) with homology to the sulfated mammalian hormones gastrin II and cholecystokinin (CCK). The leucosulfakinin (LSK) subfamily of neuropeptides stimulate contractions of the isolated cockroach hindgut. In this paper, we have ascertained some of the primary structural requirements of the sulfakinins for myotropic (muscle-contracting) activity. The myotropic "active core" of this family has been determined to be the C-terminal hexapeptide, though the C-terminal octapeptide (Glu-Asp-Tyr(SO3H)-Gly-His-Met-Arg-Phe-NH2) is required for full activity. The LSKs demonstrate considerable tolerance to Ala substitution in positions 7 and 9 within the active core without complete loss of activity. Conversely, Ala substitution in positions 8, 10 and 11 led to inactive compounds. Basicity is a critical feature of LSK position 10, while aromatic character is an important characteristic for positions 8 and 11 for myotropic activity. Only trace activity could be observed upon replacement of the Tyr(SO3H) residue in LSK-position 6 with a Ser(SO3H). One analog ([3MeHis8] LSK) proved more active as a contractile stimulant than the natural product, while another ([7-11,Tyr(SO3H)7] LSK), conversely, demonstrated inhibition of spontaneous contractions of the cockroach hindgut.
...
PMID:Structure-activity relationships for myotropic activity of the gastrin/cholecystokinin-like insect sulfakinins. 252 Jul 54

ACE (angiotensin-converting enzyme; peptidyl dipeptidase A; EC 3.4.15.1), cleaves C-terminal dipeptides from active peptides containing a free C-terminus. We investigated the hydrolysis of cholecystokinin-8 [CCK-8; Asp-Tyr(SO3H)-Met-Gly-Trp-Met-Asp-Phe-NH2] and of various gastrin analogues by purified rabbit lung ACE. Although these peptides are amidated at their C-terminal end, they were metabolized by ACE to several peptide fragments. These fragments were analysed by h.p.l.c., isolated and identified by comparison with synthetic fragments, and by amino acid analysis. The initial and major site of hydrolysis was the penultimate peptide bond, which generated a major product, the C-terminal amidated dipeptide Asp-Phe-NH2. As a secondary cleavage, ACE subsequently released di- or tri-peptides from the C-terminal end of the remaining N-terminal fragments. The cleavage of CCK-8 and gastrin analogues was inhibited by ACE inhibitors (Captopril and EDTA), but not by other enzyme inhibitors (phosphoramidon, thiorphan, bestatin etc.). Hydrolysis of [Leu15]gastrin-(14-17)-peptide [Boc (t-butoxycarbonyl)-Trp-Leu-Asp-Phe-NH2] in the presence of ACE was found to be dependent on the chloride-ion concentration. Km values for the hydrolysis of CCK-8, [Leu15]gastrin-(11-17)-peptide and Boc-[Leu15]gastrin-(14-17)-peptide at an NaCl concentration of 300 mM were respectively 115, 420 and 3280 microM, and the catalytic constants were about 33, 115 and 885 min-1. The kcat/Km for the reactions at 37 degrees C was approx. 0.28 microM-1.min-1, which is approx. 35 times less than that reported for the cleavage of angiotensin I. These results suggest that ACE might be involved in the metabolism in vivo of CCK and gastrin short fragments.
...
PMID:Novel activity of angiotensin-converting enzyme. Hydrolysis of cholecystokinin and gastrin analogues with release of the amidated C-terminal dipeptide. 255 81

Using the "Bi-Digital O-Ring Test Imaging Technique", the author has been able to accurately localize meridians and acupuncture points that correspond to specific internal organs and has found that most general patterns of meridians and the number of acupuncture points on each of the meridians of specific internal organs of the 12 main internal organs described in the literature of ancient Chinese medicine, are more or less correct, with the exception of some variations and inaccuracies. Each meridian of specific internal organs was found to be connected to the organ representation area in the cerebral cortex of specific internal organs. The acupuncture point has an area and occupies 3-dimensional space. It has a circular or slightly oval boundary with diameter in the range of 3 mm to 2.7 cm, although 6-12 mm are the most common diameters in human adults, with the exception of the area outside the corners of the nailbeds of the fingers and toes. Using the "Bi-Digital O-Ring Test Molecular Identification Method", the author also found that within the boundary of most acupuncture points and meridian lines (including Heart, Stomach, and Triple Burner) were high concentrations of neurotransmitters and hormones, including Acetylcholine, Methionine-Enkephalin, Beta-Endorphin, ACTH, Secretin, Cholecystokinin, Norepinephrine, Serotonin, and GABA. On all these meridian lines, in addition to the above neurotransmitters and hormones, Dopamine, Dynorphin 1-13, Prostaglandin E1 (PGE1) and VIP were found, but the latter do not usually exist within the boundary of the acupuncture point with the exception of the center midline of the acupuncture point where the meridian line is situated. Serotonin, Norepinephrine, and Cholecystokinin appeared in either one of the above 2 patterns, depending on the individual. Usually, no significant amounts of these neurotransmitters and hormones were found at the surrounding area outside of meridian and acupuncture points. However, the essential amino acid L-Tryptophan (which is a precursor of Serotonin), was usually found outside of the boundary of the acupuncture point and the meridian but not within the boundary of the acupuncture point and the meridian. Wherever Serotonin appeared, L-Tryptophan disappeared significantly and when the Serotonin disappeared, L-Tryptophan reappeared. In addition to the above common neurotransmitters and hormones, the Heart meridian had additional Atrial Natriuretic Peptide in both the meridian and its acupuncture points. Similarly, the Stomach meridian had additional Gastrin in both the meridian and its acupuncture points. Likewise,the Triple Burner meridian had additional Testosterone (in the male) and Estrogen (especially Estriol and Estradiol in the female.
...
PMID:Connections found between each meridian (heart, stomach, triple burner, etc.) & organ representation area of corresponding internal organs in each side of the cerebral cortex; release of common neurotransmitters and hormones unique to each meridian and corresponding acupuncture point & internal organ after acupuncture, electrical stimulation, mechanical stimulation (including shiatsu), soft laser stimulation or QI Gong. 257 47

The autonomic nervous system includes, side by side with the sympathetic and parasymathetic systems, a third, non-adrenergic and non-cholinergic system called NANC. The mediators in this system are peptides acting as neurotransmitters, i.e. neuropeptides. The NANC system has two components: bronchodilator and bronchoconstrictor. The bronchial relaxant system, called non-adrenergic inhibitory system, has several neurotransmitters, viz.: vasoactive intestinal peptide (VIP), isoleucine histidine peptide (IHP) and methionine histidine peptide (MPH), all derived from a common precursor: pre-pro VIP. MHP has been described in man and IHP in some animal species. VIP relaxes the bronchial smooth muscle, is vasodilator and exerts cellular effects in phagocytes, lymphocytes and mast cells. VIP receptors are present on cells. The other component, called non-cholinergic excitatory system, has tachykinins as neuromediators, including substance P, neurokinins A and B, neuropeptide K and calcitonin gene related peptide (CGRP). Substance P contracts the bronchi, increases mucus secretion, dilates vessels and also exerts cellular effects in lymphocytes and phagocytes. Tachykinins act through receptors 3 types of which are now known: NK 1, NK 2 and NK 3. Other neuropeptides have been isolated, including galanin, neuropeptide Y, bombesin, gastrin releasing peptide, enkephalins and katacalcin. The coexistence, in pre- and post-synaptic positions, of the conventional mediators (noradrenaline, acetylcholine) and neuropeptides leads to the concept of co-transmission and makes the notion of nerve impulse transmission more complex. The development of neuropeptide agonists and antagonists opens new therapeutic prospects in the management of asthma.
...
PMID:[Neuropeptides and respiratory diseases: prospects in the treatment of asthma]. 257 26

Immunohistochemical and chromatographic studies were performed on the guinea pig anterior pituitary gland with an antiserum recognizing an epitope within the gastrin releasing peptide (GRP) carboxyterminal amino acid sequence Val-Gly-His-Leu-Met-NH2. Within the anterior pituitary gland GRP-like immunoreactive cells were identified. The GRP-like immunoreactive cells were distributed heterogenously in the gland, predominantly located in ventral aspects of the anterior pituitary. Intracellularly, the immunoreactivity elements were identified as granula-like structures in the cytoplasma. To further characterize the peptide displaying GRP-like immunoreactivity within the pituitary cells, the GRP-like substances were analyzed by radioimmunoassay and gel filtration chromatography. Using this analytical approach it was determined that the guinea pig pituitary extract contained a peptide with characteristics similar to that of authentic porcine GRP(1-27). Only trace amounts of smaller C-terminal fragments were identified. These results indicate, in contrast to findings in other tissues, the GRP(1-27) is not further degraded into smaller peptide fragments.
...
PMID:Gastrin releasing peptide (GRP) is present in a GRP(1-27) form in anterior pituitary cells of the guinea pig. 258 23

We describe here the properties of tert-butyloxycarbonyl-Trp-Leu-Asp-Phe-NHNH2 (A-57696), a C-terminal hydrazide analogue of tert-butyloxycarbonyl-CCK4 (Boc-Trp-Met-Asp-Phe-NH2), at four cholecystokinin (CCK) receptor-bearing tissues, the guinea pig pancreas and gall bladder (Type A), guinea pig cortex (Type B), and NCI-H345 cells, a human small cell lung cancer cell line that expresses CCK-B/gastrin receptors. Using 125I-Bolton-Hunter-cholecystokinin octapeptide (26-33) (125I-Bolton-Hunter-CCK8) as the radioligand, A-57696 was found to be selective for cortical CCK-B receptors (IC50 = 25 nM), compared with pancreatic CCK-A receptors (IC50 = 15 microM). A-57696 behaved as a competitive antagonist in reversing CCK8-stimulated pancreatic amylase secretion and phosphoinositide breakdown. By Schild analysis, its Kd was determined to be 4.7 and 6.8 microM in amylase and phosphoinositide assays, respectively. A-57696 (100 microM) did not elicit gall bladder contraction, and it inhibited contractions induced by CCK8. The Kd of A-57696 at gall bladder CCK-A receptors was 19 microM. In contrast, A-57696 behaved as a partial agonist (80% of maximal CCK8 response) in stimulating calcium mobilization at CCK-B/gastrin receptors on NCI-H345 cells. A-57696 and CCK8 inhibited each other in calcium mobilization experiments utilizing the fluorescent dye Indo-1. Stimulatory actions of CCK8 and A-57696 were reversed by the CCK-B-selective (R)-L-365,260 (100 nM), whereas at the same concentration, the CCK-A-selective (S)-L-365,260 was ineffective. Binding studies using 125I-Bolton-Hunter-CCK8 and 125I-gastrin indicated that binding sites labeled by these two ligands displayed similar affinities for CCK8, desulfated CCK8, gastrin, A-57696, and both enantiomers of L-365,260. A-57696 represents a new class of CCK-A peptide antagonist at guinea pig pancreas a new class of CCK-A peptide antagonist at guinea pig pancreas and gall bladder. Its contrasting functional activities at guinea pig CCK-A and CCK-B/gastrin receptors in a human tumor cell demonstrate that, in addition to the previously described differences in binding specificity for selective agonists and antagonists, CCK-A receptors and CCK-B/gastrin receptors have different requirements for activation.
...
PMID:Distinct requirements for activation at CCK-A and CCK-B/gastrin receptors: studies with a C-terminal hydrazide analogue of cholecystokinin tetrapeptide (30-33). 260 85

Perisulfakinin, a peptide with sequence similarity to gastrin and cholecystokinin, was isolated from the corpora cardiaca of the American cockroach. Its sequence was determined to be Glu-Gln-Phe H-Asp-Asp-Tyr(SO3H)-Gly-His-Met-Arg-Phe-amide. The peptide induced hindgut contractions in the same species at concentrations as low as 250 pM. A related non-sulfated peptide was also isolated and sequenced; it was found to be identical with non-sulfated leucosulfakinin II (pGlu-Ser-Asp-Asp-Tyr-Gly-His-Met-Arg-Phe-amide). This peptide did not stimulate hindgut contractions. The structures of the cockroach peptides of the leucosulfakinin family are thus much more conserved than the cockroach hypertrehalosemic hormones.
...
PMID:Isolation and structure of two gastrin/CCK-like neuropeptides from the American cockroach homologous to the leucosulfakinins. 261 21

COOH-terminal decapeptide of gastrin-releasing peptide (GRP-10) is a bombesin-like peptide, which has bioactivities to stimulate gastrin, insulin, and glucagon secretion. We have synthesized an analogue of GRP-10 that inhibits GRP-10's stimulation of insulin secretion both in vivo and in vitro and glucagon secretion in vivo, while potentiating the stimulation of gastrin secretion. The amino acid sequence of this peptide is H-Gly-Asn-Trp-Ala-Ala-Gly-His-Leu-Met-NH2 ([Ala6]GRP-10). Because the stimulation of insulin and gastrin secretion by GRP-10 has been ascribed to a direct effect on B- and G-cells, these findings suggest that there are two subtypes of receptors for bombesin-like peptides in mammalian tissues.
...
PMID:[Ala6]gastrin-releasing peptide-10: an analogue with dissociated biological activities. 266 16

A series of 31 colorectal and 13 gastric primary human tumours were screened for their growth response to human gastrin-17 in vitro, as assessed by 75Se-seleno-methionine incorporation. Fifty-five percent of colorectal and 69% of gastric tumours showed a significant trophic response to the hormone. The responses were achieved at physiological gastrin concentrations (post-prandial circulating gastrin levels) in 35% of colorectal and 55% of gastric tumours. Lymphocytes from tumour-associated lymph nodes showed no response to the hormone and "normal" mucosal cells (obtained from the resection margin of the surgical specimen) showed lower mean levels of 75Se-seleno-methionine uptake (colorectal: 110%; gastric: 119%, expressed as a percentage of the control) when compared to tumours (colorectal: 151%; gastric: 147%). The small number of well differentiated and/or Dukes' stage A colorectal tumours examined were gastrin-responsive, but all the responsive gastric tumours were poorly differentiated. With respect to ploidy, 89% of diploid and 67% of aneuploid colorectal tumours responded trophically to gastrin. Patients with colorectal or gastric tumours may benefit from treatment with gastrin antagonists.
...
PMID:The in vitro growth response of primary human colorectal and gastric cancer cells to gastrin. 270 74

Gastrin antagonists may be useful in the treatment of peptic ulcer disease and gastrointestinal malignancies. The aim of the present study was to synthesize gastrin analogues and test them for their ability to inhibit gastrin-stimulated acid secretion. Five peptides were synthesized: peptide [2], in which methionine was replaced by leucine, and the COOH-terminal amide was replaced by the thiomethylamide; peptide [3], in which the COOH-terminal phenylalanine was removed, and the aspartic acid thioamidated; peptide [5], in which methionine was replaced by leucine, and the peptide bond between leucine and aspartic acid was replaced by a thioamide; peptide [7], in which the bond between leucine and aspartic acid was replaced by a ketomethylene amino bond; and, finally, peptide [8], in which a beta-bend was induced in the COOH-terminal region by the introduction of a D-phenylalanine in place of glycine. The biologic effect of the peptides was tested in the totally isolated, vascularly perfused rat stomach. The peptides were tested in concentrations of 10(-9), 10(-7), and 10(-5) M for agonist activity and together with gastrin 1-17, 5.2 X 10(-10) M, at a concentration of 10(-5) M for antagonist activity. Peptide [2] had full biologic activity but greatly reduced potency, and peptide [7] had a faint biologic activity. None of the peptides showed any antagonist activity.
...
PMID:Bioactivity studies on new gastrin analogues. 276 57

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