Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peptides with opioid activity are found in pepsin hydrolysates of wheat gluten and alpha-casein. The opioid activity of these peptides was demonstrated by use of the following bioassays: 1) naloxone-reversible inhibition of adenylate cyclase in homogenates of neuroblastoma X-glioma hybrid cells; 2) naloxone-reversible inhibition of electrically stimulated contractions of the mouse vas deferens; 3) displacement of [3H]dihydromorphine and [3H-Tyr, dAla2]met-enkephalin amide from rat brain membranes. Substances which stimulate adenylate cyclase and increase the contractions of the mouse vas deferens but do not bind to opiate receptors are also isolated from gluten hydrolysates. It is suggested that peptides derived from some food proteins may be of physiological importance.
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PMID:Opioid peptides derived from food proteins. The exorphins. 37 81

Protein malnutrition during suckling period or throughout the life affects the hypothalamic beta-endorphinergic system of adult rats. In the present study, rats were undernourished during suckling by feeding their dams an 8% casein diet whereas well-nourished dams received a 25% casein diet from birth until weaning (21 day of postnatal life). After weaning, the offsprings were maintained with the same diet as their dams. When rats were 3 month-old, they were subjected to two-way active avoidance task. Protein malnutrition did not affect the performance in the two-way active avoidance task. Post-training beta-endorphin or Met-enkephalin administration impaired the retention of shuttle avoidance task in both well-nourished and undernourished rats. However, the amnesic effect of the peptides was only achieved in undernourished rats with higher doses of opioids when compared to the well-nourished rats. These data suggest that undernourished rats present alterations in opioid sensitivity which may be related to changes in the levels of beta-endorphin previously observed both in brain and hypothalamus of early undernourished adult rats.
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PMID:Effects of post-training beta-endorphin and Met-enkephalin administration on two-way active avoidance task in well-nourished and protein malnourished rats. 130 Jan 56

The hypothalamic beta-endorphin system of young Wistar rats of both sexes (21-day-old) responds in a distinct way to behavioral situations when compared to adult rats (90 to 120-day-old). In the present study we investigated whether the post-training amnestic effect of beta-endorphin previously demonstrated in Wistar adult rats is also observed in young (21-day-old) well-nourished and undernourished rats. Rats were undernourished since birth by feeding their dams an 8% casein diet, while well-nourished offspring were fed by dams maintained on a 20% casein diet. beta-endorphin was administered after training in a step-down inhibitory avoidance task using a 0.2- or 0.8-mA footshock. Retention was tested 24 h later. We observed that the dose of beta-endorphin (1 microgram/kg, ip) previously reported to have an amnestic effect on adult rats was ineffective in weanling rats of both nutritional groups. At a higher dose (2 micrograms/kg, ip) and using a 0.2-mA shock, beta-endorphin impaired the retention only of well-nourished rats. Test-to-training difference (in s) in step-down latency for well-nourished beta-endorphin-treated rats was 7 vs 25 s for well-nourished rats treated with saline (P < 0.05). Undernourished rats were hyperreactive to this shock intensity. Footshock escape latency (in s) for undernourished rats was 3.56 vs 5.80 for well-nourished rats (P < 0.05, experiment 1) and 5.01 vs 10.89 (P < 0.05, in experiment 2) and showed better retention than did well-nourished rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of undernutrition during suckling on footshock escape behavior and of post-training beta-endorphin administration on inhibitory avoidance task test behavior of young rats. 134 23

Tartrate-resistant acid phosphatase (TRAcP) is a reliable cytochemical marker for the diagnosis of hairy cell leukemia (HCL). The enzyme has been the subject of much biochemical investigation yet its function in the hairy cells (HC) is still unknown. Two TRAcPs have been purified from HCL spleen tissues by a series of chromatographic separations. The two enzymes, provisionally called peak 1 and peak 2, had specific activities of greater than 600 U/mg and 800 U/mg respectively when p-nitrophenyl phosphate (p-NPP) was used as substrate and had Km values in the range of 1 to 5 mM p-NPP. The two TRAcPs had the same substrate specificities and inhibitor sensitivities, therefore could be isoforms of the same enzyme. Their pH optima were between 5 and 6 for all substrates tested including the phosphotyrosine-containing peptide, Raytide, which was still hydrolyzed efficiently at neutral pH. Neither phosphoserine nor phosphoserine-containing casein were hydrolyzed by either enzyme. The TRAcPs of HC may thus be capable of functioning as protein-tyrosine phosphatases (PTP). High activity of a PTP could regulate the activities of protein-tyrosine kinases and thereby influence the growth and differentiation of the hairy cells.
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PMID:Protein-tyrosine phosphatase activity of hairy cell tartrate-resistant acid phosphatase. 156 56

Undernutrition during suckling causes a decrease in hypothalamic beta-endorphin-like immunoreactivity in rats. Since proline endopeptidase (E.C. 3.4.21.26) has been proposed to play a role in the processing of beta-endorphin, we examined the effects of undernutrition during suckling on the enzyme activity. Rats were undernourished by feeding their dams an 8% casein diet from the day of birth until weaning (21 days). Dams of well-nourished rats were fed a 25% casein diet during the same period. After weaning, all rats received a 20% protein diet until 90 to 120 days of age when they were killed for the enzyme assay. The specific and total activity of hypothalamic proline endopeptidase was not altered by undernutrition followed by nutritional rehabilitation (2.37 +/- 0.24 nmol sulphamethoxazole min-1 mg-1 for well-nourished rats vs 2.68 +/- 0.24 nmol sulphamethoxazole min-1 mg-1 for undernourished rats). This lack of correlation suggests that proline endopeptidase is probably not responsible for the low levels of hypothalamic beta-endorphin found in adult rats submitted to undernutrition during suckling.
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PMID:Undernutrition during suckling does not change the specific or total activity of hypothalamic proline endopeptidase in adult rats. 253 6

Rats were submitted to a normal (25% casein) or a low protein diet (8% casein) from the day of birth until the age of 110 to 120 days. Hypothalamic beta-endorphin-like immunoreactivity was lower in the animals raised and maintained with the low protein diet, and, in addition, it did not respond to training in a step-down inhibitory avoidance task with or without footshock with a depletion, as was the case with the normal diet animals. In the animals submitted to the normal protein diet posttraining ACTH (0.2 micrograms/kg) and beta-endorphin (1.0 micrograms/kg) caused retrograde amnesia of a step-down inhibitory avoidance task, and pretest administration of these substances had no effect of its own, but was able to reverse the amnesia induced by their previous posttraining administration. In the animals submitted to the low protein diet, results were similar except that pretest beta-endorphin caused amnesia on its own. On the basis of previous findings which suggest that pretest actions of ACTH and beta-endorphin depend on their endogenous release at the time of training, the present results are compatible with a malfunction of the brain beta-endorphin system in the undernourished animals.
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PMID:Effect of posttraining and pretest beta-endorphin and ACTH administration in normal and protein malnourished rats. 256 Jan 73

Of three casein phosphatases isolated from the cytosol of human cord blood erythrocytes two were cobalt-dependent, E2 and E3. In the presence of CoCl2, E2 activity was the most prominent. In addition to casein, E2 dephosphorylated phosvitin and p-nitrophenyl phosphate (p-NPP) with pH optima at 6.8-7.2 for proteins and 9.0 for p-NPP. The native enzyme had a molecular weight of 104,000 daltons after AcA-44 Ultrogel filtration. According to SDS/PAGE it consisted of two subunits, 78,000 and 15,000 daltons. The 104,000-dalton form exhibited Michaelis-Menten kinetics and had the greatest affinity for casein between protein substrates tested. Ethanol denaturated the enzyme by 80%. Optimal activation of E2 phosphatase was achieved with 5 mmol/l CoCl2 which did not affect the catalytic properties of the enzyme but did affect the rate of 'E-S' complex formation. Inorganic pyrophosphate was not inhibitory for the 104,000-dalton enzyme. Judging by all these properties the natural substrate for E2 casein phosphatase could be P-pyruvate kinase.
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PMID:Cobalt-dependent protein phosphatases from human cord blood erythrocytes. II. Further characterization of E2 casein phosphatase. 283 85

Self recently described a substrate system for alkaline phosphatase (AP)-dependent ELISAs which markedly increased sensitivity, compared to using p-nitrophenyl phosphate. This increase is achieved by having AP, the primary enzyme, produce an activator for a secondary enzyme-substrate system, within which marked amplification occurs. We adapted this technique to study antibodies to casein, bovine serum albumin, ovalbumin, and cardiolipin in the sera of patients with systemic lupus erythematosus (SLE) and normal individuals. The new substrate system yielded titres 30-50-fold higher than those with p-nitrophenyl phosphate (Sigma 104, p-NPP). In addition, when used in a solid-phase C1q binding assay we were able to use a 1 : 100,000 dilution of AP-conjugated anti-human IgG with the amplified substrate, compared to the 1 : 1000 dilution needed with p-NPP. This system is extremely valuable because of its flexibility. It can either be very sparing of limited samples, or if the added sensitivity is not needed, 100-fold less AP conjugate may be used. Thus rare or expensive conjugates can be significantly conserved.
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PMID:A substrate amplification system for enzyme-linked immunoassays. Demonstration of its general applicability to ELISA systems for detecting antibodies and immune complexes. 349 82

Ten-week-old female obese and lean Zucker rats were given access to three separate macronutrient sources (casein, starch, and lard) for 7 days. They were then either adrenalectomized (ADX) or given a sham operation. Rats were assigned to one of three groups and given a daily injection of either 0, 2, or 10 mg of corticosterone. They continued to select a diet for another 17 days, after which they were killed, and their blood was assayed for corticosterone, adrenocorticotropin hormone (ACTH), insulin, glucose, and triglyceride. Retroperitoneal and parametrial fat depots were excised and sampled for lipoprotein lipase activity, fat cell size, and number. Body composition was also determined. Selection patterns of lean and obese rats were markedly affected by both ADX and corticosterone replacement. All three groups of sham-operated obese rats ate significantly more fat than did sham-operated lean rats. Adrenalectomy significantly reduced fat intakes in both obese and lean rats. Corticosterone therapy restored fat appetites of lean and obese rats in a dose-dependent fashion. In comparison to ADX lean rats, ADX obese rats reduced their normally elevated levels of blood glucose, plasma triglycerides, and insulin to within normal limits. Similarly, adipose cellularity of the ADX obese rats was reduced to that of sham-operated lean rats. Carcass fat was significantly reduced after adrenalectomy. Corticosterone therapy prevented the reduction in a dose-dependent way.
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PMID:Some metabolic and behavioral effects of adrenalectomy on obese Zucker rats. 377 20

Cholera toxin catalyzed the ADP-ribosylation of the pituitary protein hormones thyrotropin (TSH), lutropin (LH), follitropin (FSH), human chorionic gonadotropin (hCG), and corticotropin (ACTH)1-24, and ADP-ribosylation of the basic proteins histone subfraction H1 and protamine. Casein and phosvitin, acidic nuclear proteins, did not act as acceptors for toxin-catalyzed ADP-ribosylation. The isolated TSH A and B subunits were tested for their ADP-ribose acceptor activity. The TSH A subunit showed fourfold greater ADP-ribose acceptor activity than the TSH B subunit. The ADP-ribose acceptor protein protamine was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis following incubation with cholera toxin under ADP-ribosylating conditions. [3H]ADP-ribose incorporated into protein from [3H]NAD migrated with the acceptor protein protamine. In the absence of added acceptor protein, the [3H]ADP-ribose incorporated into protein migrated with the A1 fragment of cholera toxin. Cholera toxin A and B subunits were isolated and tested for their ability to catalyze the transfer of ADP-ribose to protamine. The cholera toxin A subunit showed 50-fold greater ADP-ribosyltransferase activity than the B subunit. Our data indicate that a variety of adenohypophyseal hormones and regulatory proteins act as acceptors for toxin-catalyzed ADP-ribosylation. These studies may help in understanding the role of endogenous ADP-ribosyltransferases and the physiological effects of this modification of protein.
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PMID:Polypeptide hormones and chromatin-associated proteins act as acceptors for cholera toxin-catalyzed ADP-ribosylation. 625 55


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