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Biomedical subjects

M Terasawa

Publications and source records attributed to M Terasawa.

At least 19 recordsLinked to original sources
PubMed1992

Calcyclin and calvasculin exist in human platelets.

Using Ca(2+)-dependent affinity chromatography on a synthetic compound (W-7)-coupled Sepharose column, three distinct Ca(2+)-binding proteins have been identified in human platelets. The molecular mass of these three distinct proteins was estimated to be 10, 10.5, 17 kDa, respectively, by polyacrylamide gel electrophoresis in the presence of SDS. The partial amino acid sequence revealed these proteins have EF-hand structures and high homology to the predicted proteins, calcyclin, calvasculin, and calmodulin. Calcyclin and calvasculin have been considered as probably having roles in the control of cell proliferation, but the existence of these two proteins in platelets suggests that they have other intracellular functions related to the Ca(2+)-signal transduction system.

Amino Acid Sequence↗
PubMed1992

Neurocalcin: a novel calcium-binding protein from bovine brain.

A novel calcium-binding protein (molecular weight 23,000-24,000, pI 5.3-5.5), which we term neurocalcin, was identified in bovine brain. Using calcium-dependent drug affinity chromatography ((S)-P-(2-aminoethyloxy)-N-[2-(4-benzyloxycarbonylpiperazinyl++ +)-1-(P- methoxybenzyl)ethyl]-N-methylbenzene-sulfonamide dihydrochloride, W-77, -coupled Sepharose 6B), we purified neurocalcin from bovine brain. The partial amino acid sequence of neurocalcin revealed it to be an as yet unidentified protein with three putative calcium binding sites (EF-hands). Further purification and sequence analysis demonstrated the presence of four isoprotein forms designated alpha, beta, gamma 1, and gamma 2. When the 165 sequenced residues of neurocalcin beta are compared with sequences of other proteins, neurocalcin beta has a 38.2% sequence homology with visinin and 45.5% with recoverin (Yamagata, K., Goto, K., Kuo, C.-H., Kondo, H., and Miki, N. (1990) Neuron 2, 469-476; Dizhoor, A. M., Ray, S., Kumar, S., Niemi, G., Spencer, M., Brolley, D., Walsh, K. A., Philipov, P. P., Hurley, J. B., and Stryer, L. (1991) Science 251, 915-918). Both visinin and recoverin are expressed specifically in retinal photoreceptors and are not found in brain. Unlike visinin and recoverin, neurocalcin is purified not only from retina but also from bovine brain. Our results suggest that neurocalcin is a recoverin-like protein expressed in bovine brain.

Amino Acid Sequence↗
PubMed1992

Neurocalcin, a novel calcium binding protein with three EF-hand domains, expressed in retinal amacrine cells and ganglion cells.

Neurocalcin (molecular weight 23,000 and 24,000) is a newly identified Ca2+ binding protein with three EF-hand domains and has a strong amino acid sequence homology with visinin and recoverin (Terasawa, M., Nakano, A., Kobayashi, R., and Hidaka, H. J. Biol. Chem. In press). We produced antibody against neurocalcin. Immunoblotting showed the presence of neurocalcin in bovine retina as well as brain, suggesting that neurocalcin was a neuron specific Ca2+ binding protein. Immunohistochemistry revealed the expression of neurocalcin in retinal amacrine cells and ganglion cells but not in the photoreceptor layer. This distribution of neurocalcin was quite different from that of visinin and recoverin. Our results suggest that neurocalcin may play an important role in a Ca2+ signal pathway of the nervous system.

Animals↗
PubMed1992

Full sequence of neurocalcin, a novel calcium-binding protein abundant in central nervous system.

We determined the cDNA sequence for neurocalcin, a novel calcium-binding protein in bovine brain. This clone (pCalN) has 582 nucleotides in the open reading frame including the termination codon TGA, 11 nucleotides of the 5' leader and 1251 nucleotides of the 3' noncoding region. The deduced amino acid sequence revealed that neurocalcin is composed of 193 amino acids, has a molecular mass of 22,284 daltons, and contains three putative calcium-binding sites (EF-hand motifs). By Northern blot analysis, 3.8kbp mRNA was detected in brain. The deduced amino acid sequence had a strong homology to visinin (46.5%) and recoverin (51.6%) in retina, suggesting that neurocalcin may play a visinin- or recoverin-like role in brain.

Amino Acid Sequence↗
PubMed1992

Suppression of the Arthus reaction by Y-24180, a potent and specific antagonist of platelet-activating factor.

A novel and potent antagonist of platelet-activating factor (PAF), Y-24180 (4-(2-chlorophenyl)-2-[2-(4-isobutylphenyl)ethyl]-6,9-dimethyl-6H- thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4] diazepine) was investigated for the effects on the skin reactions induced by chemical mediators and the Arthus reactions. In the rat dorsal skin, Y-24180 (0.1-10 mg/kg, p.o.) inhibited increase in vascular permeability by the intradermal PAF injection in a dose dependent manner and the inhibitory activity was 60 times more potent than that of WEB 2086. While even at doses as large as 10 mg/kg, p.o., it had no effect on vascular permeability in the rat skin induced by histamine, serotonin, bradykinin and leukotriene D4. On a reversed passive Arthus reaction in rat dorsal skin, Y-24180 (0.1-1 mg/kg, p.o.) markedly inhibited vascular permeability in a dose dependent manner and the inhibitory activity was 15 times more potent than that of WEB 2086. Y-24180 also inhibited the Arthus dermal reaction in rabbits (0.03-0.3 mg/kg, p.o.) and guinea pigs (0.1-1 mg/kg, p.o.). In addition, Y-24180 (0.1-10 mg/kg, p.o.) significantly reduced the exudate volume and the number of infiltrated inflammatory cells in the reversed passive Arthus pleural reaction in rats. Furthermore, in rat passive Arthus pancreatitis, Y-24180 (0.3-10 mg/kg, p.o.) significantly inhibited the dye extravasation from the pancreas. These results provide strong evidence that endogenous PAF plays an important role as a mediator in the type III allergic inflammation.

Animals↗
PubMed1992

Enhancement of host defense by Y-25510, (+-)-3-[4-(2-dimethylamino-1-methylethoxy)phenyl]-1H-pyrazolo[3,4 -b] pyridine-1-acetic acid, a novel synthetic compound. A comparison with recombinant human granulocyte colony-stimulating factor in 5-fluorouracil-treated mice.

The effect of a novel synthetic compound, Y-25510, (+-)-3-[4-(2-dimethylamino-1-methylethoxy)phenyl]-1H-pyrazolo[3,4 -b] pyridine-1-acetic acid, on recovery from long-lasting leukopenia induced by 5-fluorouracil was compared with that of recombinant human granulocyte colony-stimulating factor (rhG-CSF). When mice were administered i.p. with 5-FU (200 mg/kg) on days 0 and 7, intravenous administration of Y-25510 (100 and 1000 micrograms/kg) prevented the decrease in the peripheral leukocyte and neutrophil number and accelerated the recovery from leukopenia. Subcutaneous administration of rhG-CSF (50 micrograms/kg) did not prevent leukopenia but accelerated the recovery from leukopenia. In particular, peripheral neutrophil number increased over a normal level. The administration of Y-25510 (10, 100 and 1000 micrograms/kg) restored the decrease in the number of bone marrow cells, spleen cells, lymphocytes, neutrophils and monocytes. The administration of rhG-CSF (50 micrograms/kg) restored the decrease in the number of bone marrow cells, spleen cells, and neutrophils but not that of lymphocytes and monocytes. In fractions of bone marrow cells on day 21, the administration of Y-25510 (1000 micrograms/kg) showed a tendency of restoring the decrease in neutrophil number. In conclusion, the administration of Y-25510 prevented leukopenia and accelerated the recovery from leukopenia in the 5-FU-treated mice. It is suggested that the mechanism of the restorative action of Y-25510 is different from that of rhG-CSF. In a number of immature bone marrow cells Y-25510 has a potent stimulatory effect on the recovery from the decrease in number of hematopoietic cells, keeping a balance in number of each blood cell.

Adjuvants, Immunologic↗
PubMed1991

Application of the tryptophanase promoter to high expression of the tryptophan synthase gene in Escherichia coli.

The application of an inducible regulation system using the tryptophanase operon promoter (TPase promoter; Ptna) was examined for its high expression of the tryptophan synthase (TS) gene in Escherichia coli. The main problem in the application of Ptna for industrial purposes is catabolite repression by glucose, since glucose is the most abundant carbon source. However, this problem could be avoided by changing glucose to an organic acid, such as succinate, fumarate, malate and acetate, in the course of cultivation after glucose initially added was completely consumed. Under these conditions, L-tryptophan was also used to induce tryptophan synthase. Thus, the specific activity of TS in E. coli strain no. 168 harbouring pBR322F-Ptna TS was increased 500-fold compared to that of the cultured host strain. About 1 mol L-tryptophan/l reaction mixture was formed from indole and L-serine at 37 degrees C for 3.5 h.

Carbon↗
PubMed1991

Identification and characterization of protein kinase C-related enzymes in frog retina.

We isolated two types of protein kinase C-related enzymes (fPKC) in frog (Rana catesbeiana) retina. Three sequential steps of column chromatography of DEAE-cellulose, butyl-Toyopearl, and hydroxylapatite were carried out and resulted in the separation of two types of distinct Ca2+/phospholipid-dependent protein kinase activities. These proteins reacted with antibodies raised against synthetic peptides based on the predicted amino acid sequences of rat protein kinase C delta or zeta subspecies, and showed molecular masses of 90 and 75 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. Immunocytochemical analysis of 90 and 75K fPKC in frog retina revealed that the 75K fPKC was localized in the outer segment of cone cells and in the microvillar projections of Müller cells. These results suggested that fPKCs play differential roles on the photosignal transduction in frog retina.

Amino Acid Sequence↗
PubMed1991

Differential localization of protein kinase C isozymes in retinal neurons.

We report the immunohistochemical localization of protein kinase C isozymes (types I, II, and III) in the rabbit retina using the monospecific monoclonal antibodies MC-1a, MC-2a, and MC-3a. Using immunoblot analysis of partially purified protein kinase C preparations of rabbit retina, types II and III isozymes alone were detected. The activity of type III was the stronger. By light microscopic immunohistochemical analysis, retinal neurons were negative for type I and positive for type II and type III isozymes. Type II was more diffusely distributed through the retinal layers, but was distinctive in ganglion cells, bipolar cells, and outer segments. The immunoreactivity was stronger for type III isozyme, and it was observed in mop (rod) bipolar cells and amacrine cells. By using immunoelectron microscopy, the cytoplasm of the cell body, the axon, and dendrites of the mop bipolar cells were strongly immunoreactive for type III. The so-called rod bipolar cells were for the first time seen to form synapses with rod photoreceptor cells. These differential localizations of respective isozymes in retinal neurons suggest that each isozyme has a different site of function in each neuron.

Animals↗
PubMed1991

Ca2+/calmodulin-dependent protein phosphorylation associated with the cytoskeleton of quiescent rat fibroblast (3Y1) cells.

Endogenous phosphorylation of the crude membrane fraction of cultured 3Y1 fibroblast cells was enhanced by the addition of Ca2+/calmodulin. Both Ca2+/calmodulin-dependent protein kinase activity and its substrate were present in a cytoskeletal fraction, obtained as a pellet after washing of the membrane fraction with 2 mM EGTA, 0.6 M NaCl, and 1% Triton X-100. The phosphorylatable protein in the Triton X-insoluble fraction was identified by immunoblotting as vimentin. This endogenous phosphorylation induced by calmodulin was inhibited by the addition of KN-62, a specific Ca2+/calmodulin-dependent protein kinase II inhibitor, in a dose-dependent manner. However, phosphorylation of the 59 kDa protein (vimentin) in this fraction was not stimulated by adding both phosphatidyl serine and cAMP, thereby suggesting the absence of protein kinase C or of cAMP-dependent protein kinase in this fraction. The protein kinase associated with the Triton X-insoluble fraction phosphorylated the Ca2+/calmodulin-dependent protein kinase II-specific site of synapsin I from the bovine cortex. Two-dimensional phosphopeptide maps of vimentin indicated that a major phosphopeptide phosphorylated by the endogenous calmodulin-dependent kinase also appears to be the same as a major phosphopeptide phosphorylated by the exogenous Ca2+/calmodulin-dependent protein kinase II. Our results suggest that cytoskeleton-associated Ca2+/calmodulin-dependent protein kinase II regulates dynamic cellular functions through the phosphorylation of cytoskeletal elements in non-neural cells.

Animals↗
PubMed1991

Identification of plasmid partition function in coryneform bacteria.

We have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. This fragment was able to stabilize the unstable plasmids in cis but not in trans.

Base Sequence↗
PubMed1991

Effect of Y-20811, a long-lasting thromboxane A2 synthetase inhibitor, on antigen-induced airway hyperresponsiveness in guinea pigs.

Effect of Y-20811 on airway hyperresponsiveness was studied in sensitized guinea pigs. Airway hyperresponsiveness to acetylcholine (ACh) reached maximum 7 h after antigen challenge in guinea pigs sensitized actively. Y-20811 (0.3-3 mg/kg) administered orally 3 h prior to challenge inhibited this airway hyperresponsiveness in a dose-dependent manner. Y-20811 (3 mg/kg) administered orally 4 h after antigen challenge also decreased the airway hyperresponsiveness. On the other hand, Y-20811 did not affect the bronchoconstriction induced by ACh, serotonin and histamine in nonsensitized guinea pigs. The number of eosinophils in bronchoalveolar lavage fluid in the guinea pig reached the peak 7 h after antigen challenge. Y-20811 had a tendency to decrease the number of total cells, macrophages and eosinophils in a dose-dependent manner. These results suggest that Y-20811 suppress the asthmatic mechanism which causes antigen-induced airway hyperresponsiveness.

Acetylcholine↗
PubMed1991

[Effects of Y-20811, a specific thromboxane A2 synthetase inhibitor, on chemical mediator-induced bronchoconstriction in guinea pigs].

We investigated the effects of Y-20811 on chemical mediator-induced bronchoconstriction and the release of chemical mediators into lung perfusion fluid during arachidonic acid (AA)-induced bronchoconstriction in guinea pigs. Y-20811 (0.01-1 mg/kg, i.v.), like acetylsalicylic acid or indomethacin, dose-dependently suppressed arachidonic acid- and LTD4-induced bronchoconstriction, and it (1 mg/kg, i.v.) also inhibited PAF-induced bronchoconstriction in guinea pigs. However, at a dose of 1 mg/kg, i.v., it was inactive against the bronchoconstriction induced by histamine, serotonin and acetylcholine in guinea pigs. Y-20811 (0.3-10 mg/kg) administered orally also prevented the LTD4-induced bronchoconstriction in a dose-dependent manner. This protective effect of Y-20811 (10 mg/kg, p.o.) persisted for at least 24 hr. Y-20811 (10 mg/kg, p.o.) also inhibited antigen-induced bronchoconstriction in guinea pigs passively sensitized with anti-ovalbumin guinea pig serum and pretreated with mepyramine. In the perfused and ventilated guinea pig lungs, Y-20811 inhibited AA-induced bronchoconstriction, decreased the release of TXA2 (estimated as TXB2) and increased the release of PGE2 into the perfused lung fluid, significantly (TXB2 and PGE2 were measured by HPLC). Therefore, Y-20811 suppressed various stimulant-induced bronchoconstrictions through the decrease of TXA2 production and the increase of PGE2 production. Thus, Y-20811 should prove useful as an anti-asthmatic drug.

Animals↗
PubMed1990

KN-62, 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazi ne, a specific inhibitor of Ca2+/calmodulin-dependent protein kinase II.

1-[N,O-Bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpipera zine (KN-62), a selective inhibitor of rat brain Ca2+/calmodulin-dependent protein kinase II (Ca2+/CaM kinase II) was synthesized and its inhibitory properties in vitro and in vivo were investigated. KN-62 inhibited phosphorylation of exogenous substrate (chicken gizzard myosin 20-kDa light chain) by Ca2+/CaM kinase II with Ki value of 0.9 microM, but no significant effect up to 100 microM on activities of chicken gizzard myosin light chain kinase, rabbit brain protein kinase C, and bovine heart cAMP-dependent protein kinase type II. KN-62 also inhibited the Ca2+/calmodulin-dependent autophosphorylation of both alpha (50 kDa) and beta (60 kDa) subunits of Ca2+/CaM kinase II dose dependently in the presence or absence of exogenous substrate. Kinetic analysis indicated that this inhibitory effect of KN-62 was competitive with respect to calmodulin. However, KN-62 did not inhibit the activity of autophosphorylated Ca2+/CaM kinase II. Moreover, Ca2+/CaM kinase II bound to a KN-62-coupled Sepharose 4B column, but calmodulin did not. These results suggest that KN-62 affects the interaction between calmodulin and Ca2+/CaM kinase II following inhibition of this kinase activity by directly binding to the calmodulin binding site of the enzyme but does not affect the calmodulin-independent activity of already autophosphorylated (activated) enzyme. We examined the effect of KN-62 on cultured PC12 D pheochromocytoma cells. KN-62 suppressed the A23187 (0.5 microM)-induced autophosphorylation of the 53-kDa subunit of Ca2+/CaM kinase in PC12 D cells, which was immunoprecipitated with anti-rat forebrain Ca2+/CaM kinase II polypeptides antibodies coupled to Sepharose 4B, thereby suggesting that KN-62 could inhibit the Ca2+/CaM kinase II activity in vivo.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1990

Pharmacological actions of Y-24180: I. A potent and specific antagonist of platelet-activating factor.

The ability of Y-24180, 4-(2-chlorophenyl)-2-[2-(4-isobutylphenyl)ethyl]- 6,9-dimethyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a] [1,4]diazepine to inhibit platelet-activating factor (PAF)-induced reactions was investigated. Y-24180 (0.0003-0.003 mg/kg, i.v.) dose-dependently inhibited PAF-induced bronchoconstriction in guinea pigs, but even at a high dose of 10 mg/kg, i.v., it was either inactive or weakly active against the bronchoconstriction induced by histamine, serotonin, acetylcholine, arachidonic acid, bradykinin, or leukotriene D4. Oral doses (0.003-0.1 mg/kg) of Y-24180 also prevented hemoconcentration due to PAF in a dose dependent manner and produced a parallel shift of the PAF dose-response curve. Y-24180 (0.0003-0.1 mg/kg, i.v.) and WEB 2086 (0.03-1 mg/kg, i.v.) dose-dependently reversed PAF-induced hypotension in anesthetized rats. In mice, PAF-induced lethality was inhibited by Y-24180 and WEB 2086 with ED50 values of 0.022 and 1.42 mg/kg, p.o., and 0.023 and 0.12 mg/kg, i.v., respectively. This protective effect of Y-24180 given p.o. persisted for at least 6 hr. In actively sensitized mice lethal anaphylactic shock was prevented by oral doses of Y-24180 and WEB 2086 with ED50 values of 0.095 and 0.69 mg/kg, respectively. These results suggested that Y-24180 is an extremely potent and specific PAF antagonist with a good duration of action.

Anaphylaxis↗
PubMed1990

Pharmacological actions of Y-24180, a new specific antagonist of platelet activating factor (PAF): II. Interactions with PAF and benzodiazepine receptors.

The inhibitory effect of Y-24180, 4-(2-chlorophenyl)-2-[2-(4-isobutylphenyl)ethyl]-6,9-dimethyl-6H-t hieno [3,2-f][1,2,4]triazolo [4,3-a][1,4]diazepine, on platelet activating factor (PAF)-induced platelet aggregation and the specific binding of 3H-PAF to platelets was compared with other thienodiazepine derivatives, WEB 2086 and etizolam. Y-24180 inhibited PAF-induced rabbit platelet aggregation in vitro (IC50 3.84 nM), but had little effect on adenosine diphosphate- or arachidonic acid-induced aggregation. WEB 2086 and etizolam also showed an inhibitory effect of PAF-induced aggregation (IC50 values are 456 and 6730 nM, respectively). In PAF-induced human platelet aggregation, Y-24180 (IC50 0.84 nM) was more potent than WEB 2086 (IC50 4.21 nM) and etizolam (IC50 998 nM). Y-24180, WEB 2086 and etizolam displaced 3H-PAF binding from the washed-platelets of rabbits with an IC50 value of 3.50, 9.35 and 29.5 nM, respectively. In rabbits, pretreatment with Y-24180 and WEB 2086 antagonized PAF-induced platelet aggregation dose-dependently. The significant inhibitory effect of Y-24180 (1 mg/kg, p.o.) lasted 72 hr after a single dose oral administration. WEB 2086 (10 mg/kg, p.o.) also antagonized the ex vivo response induced by PAF 1 hr after administration, but no significant effect was observed 3 hr after administration. Y-24180 displaced 3H-diazepam binding from the synaptosomal membranes of rat cerebral cortex with a Ki value of 3.68 microM. The affinity of Y-24180 for benzodiazepine(BZP) receptors was lower than those of WEB 2086 and etizolam and was about 1000 times lower than that for PAF receptors in platelets.

Animals↗
PubMed1990

Effect of cysteine ethylester hydrochloride (Cystanin) on host defense mechanisms (V): Potentiation of nitroblue tetrazolium reduction and chemiluminescence in macrophages or leukocytes of mice or rats.

L-Cysteine ethylester hydrochloride (Cystanin, ethylcysteine) at doses of 3-30 mg/kg, p.o., potentiated the reduction of nitroblue tetrazolium (NBT) by mouse peritoneal macrophages ex vivo. In in vitro experiments, this drug (30 microM) augmented NBT reduction of mouse peritoneal macrophages induced by opsonized zymosan (OZ). At the same concentration, this drug accelerated the enhancement of the OZ-induced NBT reduction by the addition of concanavalin A, N-formyl-L-methionyl-L-leucyl-L-phenylalanine or phorbol myristate acetate. This enhancing effect of ethylcysteine was completely diminished by the addition of SOD, sodium azide and catalase. In ex vivo experiments, the OZ-induced chemiluminescence of rat peritoneal macrophages and white blood cells was enhanced by the administration of ethylcysteine at doses of 3-10 mg/kg (i.p.) and 3-30 mg/kg (p.o.). In addition, this drug significantly enhanced the lumisphere-induced chemiluminescence of rat peritoneal leukocytes at 30 mg/kg (i.p.), but not the OZ-induced chemiluminescence. In in vitro experiments, this drug (30 microM) did not enhance the OZ-induced chemiluminescence response of rat peritoneal macrophages. These results suggest that ethylcysteine may enhance the intracellular generation of antimicrobial oxidants in macrophages and leukocytes.

Animals↗