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)

Acid phosphatase activity in homogenized tibiae and femora of suckling rats was extracted with 0.3M KCl and 0.1% Triton X-100. A high-speed supernatant was treated with protamine sulfate, dialyzed, and chromatographed on CM-52 cellulose. All of the acid phosphatase activity was eluted with a sodium acetate buffer and combined ionic strength-pH gradient into two peaks (E1 and E2). Both enzyme peaks were further purified with Sephadex G-200, which resulted in 700- and 1000-fold purification for E2 and E1, respectively. A total of 220 units (mumoles substrate/min) of E2 with a specific activity of 160 units/mg protein has been obtained in one run by this procedure. E1 has a high molecular weight (greater than 100,000) and shows preference for monophosphate ester substrates, is markedly inhibited by tartrate, and has a pH optimum near 5. E2 has a lower molecular weight (greater than 40,000) and shows negligible activity with monophosphate esters [except with p-nitrophenyl phosphate (p-NPP)], but high activity with ADP and ATP. E2 is unaffected by tartrate and shows a pH optimum near 6. Both enzymes are competitively inhibited by inorganic phosphate, and E2, but not E1, is markedly inhibited by p-chloromercuribenzoate. With p-NPP as substrate, E1 and E2 have distinctly different values for Km. E1 appears similar to the high molecular weight acid phosphatases of soft tissues. However, E2 appears to differ from the low molecular weight phosphatases in soft tissues with regard to substrate specificity.
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PMID:Purification and partial characterization of two acid phosphatases from rat bone. 11 82

Extracts of tibiae of suckling rats were prepared with 0.3 M KCl containing 0.1% Triton X-100 and were chromatographed with CM-52 cellulose. Most of the acid phosphatase activity determined with p-nitrophenylphosphate (p-NPP) was bound to the cellulose and could be eluted with a sodium acetate buffer gradient in 2 distinct peaks. The major peak, E2, was bound strongly to the cellulose and showed high activity with p-NPP and inorganic pyrophosphate (P-Pi), but only slight activity with beta-glycerophosphate (beta-GP) and was unaffected by tartrate. The minor peak, E1, was weakly bound to the adsorbent, showed equal activity with p-NPP and beta-GP, but negligible activity with P-Pi and was completely inhibited by tartrate. These results support earlier evidence suggesting that bone contains at least 2 different acid phosphatases and that the more abundant enzyme may function as a pyrophosphatase.
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PMID:Chromatographic separation of two acid phosphatases from rat bone. 20 77

The pituitary glands of two urodelan species (Mertensiella caucasica, Triturus cristatus) and one one caecilian species (Chthonerpeton indistinctum) were examined with histological (Alcian blue, Brookes' trichrome stain), enzyme histochemical (acid phosphatase, alpha-naphthylacetate-esterase, acetylcholinesterase) and immunofluorescence techniques (anti-carp GTH, anti-ovine prolactin, anti-synthetic alpha-MSH). In the pituitary gland of Mertensiella and Triturus six chromophilic cell types could be distinguished. A strong fluorescence was observed in the MSH-, GTH- and TSH-cells. In the pituitary gland of Chthonerpeton only five chromophilic cell types could be distinguished: in the rostral part of the pituitary gland the B3-cell; in the basal region of the central area the B2-cell; dorsocaudally the B1-cell. The acidophilic cells were found in the central and caudal part of the pars distalis. The basophils of the pars intermedia could be observed in the dorsocaudal part of the pituitary gland surrounding the neurohypophysis. All acidophilic cells showed a strong immunofluorescence with anti-ovine prolactin (LTH).
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PMID:Histological, immuno- and enzyme-histochemical investigations on the adenohypophysis of the urodeles, Mertensiella caucasica and Triturus cristatus and the caecilian, Chthonerpeton indistinctum. 34 44

In Pseudomonas aeruginosa, the effect of different cations on the acid phosphatase activity was studied in order to acquire more information related to a previously proposed mechanism, involving the coordinated action of this enzyme with phospholipase C. Although the natural substrate of this enzyme is phosphorylcholine, in order to avoid the possible interaction of its positive charge and those of the different cations with the enzyme molecule, the artificial substrate p-nitrophenylphosphate was utilized. Kinetic studies of the activation of acid phosphatase (phosphorylcholine phosphatase) mediated by divalent cations Mg2+, Zn2+ and Cu2+ revealed that all these ions bind to the enzyme in a compulsory order (ordered bireactant system). The Km values obtained for p-NPP in the presence of Mg2+, Zn2+ and Cu2+ were 1.4 mM, 1.0 mM and 3.5 mM, respectively. The KA values for the same ions were 1.25 mM, 0.05 mM and 0.03 mM, respectively. The Vmax obtained in the presence of Cu2+ was about twofold higher than that obtained in the presence of Mg2+ or Zn2+. The inhibition observed with Al3+ seems to be a multi-site inhibition. The K'app and n values, from the Hill plot, were about 0.25 mM and 4.0 mM, respectively, which were independent of the metal ion utilized as activator. It is proposed that the acid phosphatase may exert its action under physiological conditions, depending on the availability of either one of these metal ions.
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PMID:Pseudomonas aeruginosa acid phosphatase. Activation by divalent cations and inhibition by aluminium ion. 154 81

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

An ideal in vitro model for the study of endocrine functions would be one in which cells could propagate in culture and express their specialized functions. Most endocrine studies to date have relied on primary cell culture or on the use of tumor cell lines. This report describes the characterization of three endocrine cell lines immortalized by transfecting endocrine cells with a temperature-sensitive mutant SV40 virus. Rabbit endometrium (HRE-H9), human placenta (SPA209-10) and rat pituitary (RP) cells were immortalized by SV40 virus, a temperature-sensitive (ts) mutant in the A gene, which encodes the large tumor antigen that is required for the maintenance of transformation. The transformed phenotype of the SV40 tsA mutant-immortalized cell line can be reversed simply by a shift in temperature. At the permissive temperature (34 degrees C), all three types of cells exhibited a transformed phenotype, which is characterized by high cell density growth and by the overgrowth of nontransformed cell layers. However, at the non-permissive temperature (40 degrees C) these cells reverted to a non-transformed phenotype as demonstrated by a marked decrease in the overgrowth of nontransformed layers and by the expression of differentiated functions. At the non-permissive temperature (40 degrees C), the endometrial cell line was capable of synthesizing beta-endorphin, and it exhibited hormonally regulated expression of the transfected hybrid uteroferrin gene construct. The human placenta cell line was capable of secreting GnRH upon stimulation by cAMP, forskolin, theophyllin, PGE, catecholamine and Ca++ channel stimulators. Moreover, the rat pituitary cell line was capable of synthesizing and secreting growth hormone (GH) which was stimulated by GHRH and cAMP. The advantage of the temperature-sensitive cell lines is that a single cell line is the source of both the normal and transformed states; thus, studies are internally controlled. These results demonstrate that tsA mutants of SV40 virus are the best available agents for immortalizing mammalian endocrine cells that retain differentiated functions.
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PMID:Characterization of endocrine cell lines immortalized by a temperature-sensitive mutant SV40. 165 33

The region -15 to -3 of the pro-opiomelanocortin (POMC) gene promoter specifically binds a transcription factor previously designated PO-B. This region of the POMC gene is involved in the control of constitutive POMC gene expression since mutation of the PO-B DNA-binding site severely reduces transcription from the POMC promoter both in vivo and in vitro (Riegel, A. T., Remenick, J., Wolford, R., Berard, D., and Hager, G. (1990) Nucleic Acids Res. 18, 4513-4521). We have now purified PO-B from HeLa cells approximately 25,000-fold to greater than 90% homogeneity by a combination of ion exchange and reversed phase chromatography. In addition we have studied post-translational modifications that alter the affinity of purified PO-B for its cognate DNA binding site. In Southwestern analysis of column fractions, two bands of apparent molecular masses of 54 and 56 kDa bound specifically to the PO-B recognition sequence. The two copurified components have indistinguishable amino acid composition, are highly hydrophobic, and are heat and acid stable. DNA-binding specificity studies suggest that PO-B does not represent any previously described transcription factor. In addition, dephosphorylation of both species with acid phosphatase induced an about 30-fold increase in DNA binding but failed to produce any significant change in electrophoretic mobility. We conclude that the purified PO-B species represent products of the same gene and suggest that the in vivo function of PO-B may be regulated by its phosphorylation status.
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PMID:Purification of PO-B, a protein that has increased affinity for the pro-opiomelanocortin gene promoter after dephosphorylation. 206 9

We studied the testis of Wistar rats weighing 280-300 gms. following the administration of a single, acute intracardiac dose of methionine-enkephalin (100 microliters of 50% met-enkephalin solution), or a chronic intramuscular dose (50 microliters of 40% met-enkephalin solution). Rats were sacrificed at 15, 30 and 60 minutes following acute injection. Those on chronic treatment were injected once daily for 10 or 20 days. For the study, we utilized 105 male Wistar rats; 30 comprised the control group, and 75 comprised the study group. The following staining methods were used: 1) succinate dehydrogenase, 2) lactate dehydrogenase, 3) ATPase, 4) acid phosphatase, 5) alkaline phosphatase. We observed marked histoenzymological changes in the rat testis. Particularly noteworthy was a marked change in the energy pathways consisting of a decreased activity of aerobic pathways (decreased SDH activity), increased anaerobic activity (increased LDH activity), and consequently, decreased cellular energy stores (decreased ATPase activity). Similarly, changes were observed in other nonspecific enzymes that led to a fall in acid phosphatase activity and a rise in alkaline phosphatase activity.
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PMID:[Effects of met-enkephalin on the testis. III. Histoenzymatic study]. 253 59

It has previously been shown that the steroidogenic action of adrenocorticotropic hormone (ACTH) is accompanied by characteristic alterations in cell ultrastructure. These include hypertrophy of the Golgi complex associated with increased vesicle formation and striking elevations of acid phosphatase activity in the Golgi complex and lysosomes. To investigate a possible relationship of these phenomena to steroidogenic function in monolayer cultures of murine adrenal tumor cells, monensin, a carboxylic ionophore which disrupts the ordered structure and transport function of the Golgi complex, was used. Monensin, at a concentration of 1.2 microM, causes massive vacuolization and hypertrophy of the Golgi complex. No effect on mitochondrial structure was seen. Monensin, 0.6-1.2 microM, inhibits both ACTH-stimulated and basal steroidogenesis by approximately 50% in incubations of 4 h or less. Dibutyryl-cAMP-stimulated steroidogenesis was inhibited to a similar degree. Incubations were carried out in serum-free media to eliminate possible effects due to exogenous cholesterol transport into the cell. There were no direct inhibitory effects of monensin on cholesterol side-chain cleavage (SCC) activity in isolated mitochondria. In contrast, mitochondria isolated from cells previously treated with monensin had a reduced capacity for this activity. These experiments suggest that monensin inhibits transport of cholesterol from the Golgi complex to the mitochondrial site of steroidogenesis action or interferes with the transport of key mitochondrial proteins synthesized on cytoplasmic ribosomes.
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PMID:The Golgi apparatus and adrenal function: the effects of monensin on adrenocorticotropic hormone-stimulated steroidogenesis. 298 53

The anatomical and biochemical features of primary sensory afferents and the peptidergic innervation of cremaster motoneuron efferents in the genitofemoral (Gf) nerve were analyzed in the rat using immunohistochemical, histochemical, retrograde tracing and lesion methods. Afferent fibers in the Gf nerve were shown to originate from neurons in L1 and L2 dorsal root ganglia (DRG) and to project to L1 to T12.5 in the spinal cord. Some of the DRG neurons giving rise to these fibers contained substance P (SP) or the enzyme fluoride-resistant acid phosphatase but none appeared to contain somatostatin. The dermatome area of the Gf nerve, as determined by plasma extravasation methods, was located in the rostral scrotal and adjacent abdominal region. Identification of cremaster motoneurons by retrograde labelling from the Gf nerve revealed these neurons to be located in the L1 to L2 spinal cord segment, to have prominent rostrocaudally oriented dendritic aborizations and to receive a rich innervation by fibers containing SP, thyrotropin-releasing hormone (TRH) or met-enkephalin (met-Enk). Lesion studies indicated the SP-and met-Enk-containing fibers to be supplied by local intraspinal systems and the TRH-containing fibers by supraspinal systems. In female rats, motoneurons corresponding to the male version of the cremaster motoneuronal pool were less developed and received far fewer peptidergic connections than that observed in males. The multiple neural systems innervating cremaster motoneurons together with sensory afferents in the Gf and other scrotal nerves are suggested to be involved in the contribution of cremaster muscles to thermoregulation of the scrotum.
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PMID:Neural relations of cremaster motoneurons, spinal cord systems and the genitofemoral nerve in the rat. 393 95


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