218 resultados para CA2 STORES
Resumo:
(PG)PGII (PSII) PGPSII(222 mg PGmg Chl)PSII(2440 mg PGmg Chl) PGPSIIPGPSII-- PG16201500 cm-1;35003100 cm. -1 PGPSIIPSIIPGPSII;Ca2+PGPSII(dcPSII)Ca2+ PGdcPSIIa-p_PSIIPGCa2+PSII
Resumo:
IIYZ(D1-Y161)IIII(OEC) PSII LaCl3TbCl3Co2Ni2PSII 1. PSII , -PSII; 2. PSII , CaCl2Ca2+Mn3(III)>Mn(III)Mn(III)> Mn(III)Mn(IV) 3. LaCl3 TbCl3 IILa3+Tb3+IICa2+Ca2+ 10 mmol/L Ca2+50%50%PSII10 4Ni2Co2IINi2Co2II17 kDa23 kDaIICaCl25 mmol/L17 kDa10 mmol/L17 kDa 23 kDaMnCa
Resumo:
PSII 1. PSII ; 2. PSII H568WM01Z342, H568WM01CaCl2Z342Ca2+ 3. Mn/CaPSII , wwg-27CaIICaMnCl2 4. MnCl2PSII pH
Resumo:
Iphotosystem IPSIPSI14Ilight-harvesting complex I, LHCI4LhcaplastocyaninPCferredoxinFdPSIPSIQin et al., 2007PSI 1PSI PSIBassi and Simpson, 1987; Croce et al., 1998; Psllon et al.1995; Schmid et al. 2002PSI20hPSI25-60hPSITriton X-100(n-Dodecyl -D-maltoside, DDM)PSI100,000gBeckman VTi 500.1-1 mol/L3hPSIDDM3-(N, N-Dimethylpalmitylammonio) propanesulfonate zw 3-16PSI100,000gBeckman VTi 504hPSI coreLHCI-680LHCI-730HPLCLhca1.5-1.61.0, 0.8-1.1 -LHCILHCI 2PSI PSIPSIpH 5-10PSILHCIMg2+Ca2+Na+LHCI-680LHCI-730;PSISDS-PAGELHCI-730LHCI-680LHCILHCI-680LHCI-680 3PSILHCI 2500 molm-2s-1PSISDS-PAGEPSIPSIPSIPSIChlO21000 molm-2s-1300 molm-2s-1LHCI-680LHCI-730LHCI-680LHCI-730LHCILHCI-680LHCI-730Chl 4light-harvesting complexLHCPSI PSIPSI-LHCIIPSIPSI core2500 molm-2s-1PSIP700PSI-LHCIIPSIPSI coreIIChl a/bIIlight-harvesting complex IILHCIIPSI corePSI-LHCIILHCIILHCIIPSI-LHCII;LHCIPSI corePSI corePSI
Resumo:
A specific blood coagulation factor X activator was purified from the venom of Ophiophagus hannah by gel filtration and two steps of FPLC Mono-Q column ion-exchange chromatography. It showed a single protein band both in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and alkaline polyacrylamide gel electrophoresis. The mol. wt was estimated to be 62,000 in non-reducing conditions and 64,500 in reducing conditions by SDS-PAGE. The isoelectric point was found to be pH 5.6. The enzyme had weak amidolytic activities toward CBS 65-25, but it showed no activities on S-2266, S-2302, thrombin substrate S-2238, plasmin substrate S-2251 or factor Xa substrate S-2222. It had no arginine esterase activity toward substrate benzoylarginine ethylester (BAEE). The enzyme activated factor X in vitro and the effect was absolutely Ca2+ dependent, with a Hill coefficient of 6.83. It could not activate prothrombin nor had any effect on fibrinogen and thus appeared to act specifically on factor X. The procoagulant activity of the enzyme was almost completely inhibited by serine protease inhibitors like PMSF, TPCK and soybean trypsin inhibitor; partially inhibited by L-cysteine. Metal chelator EDTA did not inhibit its procoagulant activity. These results suggest that the factor X activator from O. hannah venom is a serine protease.
Resumo:
A specific activator of blood coagulation factor X was purified from the venom of Bungarus fasciatus by gel filtration and by ion-exchange chromatography on a Mono-Q column (FPLC). It consisted of a single polypeptide chain, with a mel. wt of 70,000 in reducing and non-reducing conditions. The enzyme had an amidolytic activity towards the chromogenic substrates S-2266 and S-2302 but it did not hydrolyse S-2238, S2251 or S-2222, which are specific substrates for thrombin, plasmin and factor Xa, respectively. The enzyme activated factor X in vitro and the effect was Ca2+ dependent with a Hill coefficient of 7.9. As with physiological activators, the venom activator cleaves the heavy chain of factor X, producing the activated factor Xa alpha. The purified factor X activator from B. fasciatus venom did not activate prothrombin, nor did it cleave or clot purified fibrinogen. The amidolytic activity and the factor X activation activity of the factor X activator from B. fasciatus venom were readily inhibited by serine protease inhibitors such as diisopropyl fluorophosphate (DFP), phenylmethanesulfonyl fluoride (PMSF), benzamidine and by soybean trypsin inhibitor but not by EDTA. These observations suggest that the factor X activator from B. fasciatus venom is a serine protease. It therefore differs from those of activators obtained from Vipera russelli and Bothrops atrox venoms, which are metalloproteinases.
Resumo:
A platelet glycoprotein Ib-binding protein, termed TSV-GPIb-BP, was isolated from the venom of Trimeresurus stejnegeri. On SDS-polyacrylamide gel electrophoresis, TSV-GPIb-BP showed a single band with an apparent molecular weight of 28,000 and two distinct bands with apparent molecular weights of 16,000 and 15,000 under non-reducing and reducing conditions, respectively. cDNA clones containing the coding sequences for both TSV-GPIb-BP subunits were isolated and sequenced. The deduced amino acid sequences of TSV-GPIb-BP subunits were confirmed by N-terminal protein sequencing and trypsin-digested peptide mass fingerprinting. Interestingly, the a subunit of TSV-GPIb-BP is identical to that of alboaggregin-B, and the sequence identity of their beta subunits is 94.3%. TSV-GPIb-BP inhibited ristocetin-induced human platelet agglutination in platelet-rich plasma under lower dosages (<5 mug/ml). On the other hand, it directly aggregated washed human platelets in the absence of additional Ca2+ or any other cofactors under higher dosages (>5 mug/ml). This platelet aggregation activity was dose-dependently inhibited by specific GPIbalpha antibodies, but not by those antibodies against platelet GPIa, GPIIa, GPIIb and GPIIIa. (C) 2003 Elsevier Science Ltd. All rights reserved.
Resumo:
In mammals, trefoil factor family (TFF) proteins are involved in mucosal maintenance and repair, and they are also implicated in tumor suppression and cancer progression. A novel two domain TFF protein from frog Bombina maxima skin secretions (Bm-TFF2) has been purified and cloned. It activated human platelets in a dose-dependent manner and activation of integrin a(11b)beta(3) was involved. Aspirin and apyrase did not largely reduce platelet response to Bm-TFF2 (a 30% inhibition), indicating that the aggregation is not substantially dependent on ADP and thromboxane A2 autocrine feedback. Elimination of external Ca2+ with EGTA did not influence the platelet aggregation induced by Bm-TFF2, meanwhile a strong calcium signal (cytoplasmic Ca2+ release) was detected, suggesting that activation of phospholipase C (PLC) is involved. Subsequent immunoblotting revealed that, unlike in platelets activated by stejnulxin (a glycoprotein VI agonist), PLC gamma 2 was not phosphorylated in platelets activated by Bm-TFF2. FITC-labeled Bm-TFF2 bound to platelet membranes. Bm-TFF2 is the first TFF protein reported to possess human platelet activation activity. (c) 2005 Elsevier Inc. All rights reserved.
Resumo:
A phospholipase A(2) (PLA(2)) called jerdoxin, was isolated from Trimeresurus jerdonni snake venom and partially characterized. The protein was purified by three chromatographic steps. SDS-polyacrylamide gel electrophoresis in the presence or absence of dithiothreitol showed that it had a molecular mass of 15 kDa. Jerdoxin had an enzymatic activity of 39.4 mumol/min/mg towards egg yolk phosphatidyl choline (PC). It induced edema in the footpads of mice. In addition, jerdoxin exhibited indirect hemolytic activity. About 97% hemolysis was observed when 2 mug/ml enzyme was incubated for 90 min in the presence of PC and Ca2+. No detectable hemolysis was noticed when PC was not added. Ca2+ was necessary for jerdoxin to exert its hemolytic activity, since only 52% hemolysis was seen when Ca2+ was absent in the reaction mixture. Furthermore, jerdoxin inhibited ADP induced rabbit platelet aggregation and the inhibition was dose dependent with an IC50 of 1.0 muM. The complete amino acid sequence of jerdoxin deduced from cDNA sequence shared high homology with other snake venom PLA(2)s, especially the D49 PLA(2)s. Also, the residues concerned to Ca2+ binding were conserved. This is the first report of cDNA sequence of T jerdonii venom PLA(2). (C) 2002 Elsevier Science Ltd. All rights reserved.
Resumo:
Purkinje cell degeneration (pcd) mice are characterized by death of virtually all cerebellar Purkinje cells by postnatal day 30. In this study, we used DNA microarray analysis to investigate differences in gene expression between the brains of wild type and pcd mice on postnatal day 20, before the appearance of clear-cut phenotypic abnormalities. We identified 300 differentially expressed genes, most of which were involved in metabolic and physiological processes. Among the differentially expressed genes were several calcium binding proteins including calbindin -28k, paravalbumin, matrix gamma-carboxygluta mate protein and synaptotagamins 1 and 13, suggesting the involvement of abnormal Ca2+ signaling in the pcd phenotype.
Resumo:
Acid-sensing ion channels (ASICs) composed of ASIC1a subunit exhibit a high Ca2+ permeability and play important roles in synaptic plasticity and acid-induced cell death. Here, we show that ischemia enhances ASIC currents through the phosphorylation at Ser478 and Ser479 of ASIC1a, leading to exacerbated ischemic cell death. The phosphorylation is catalyzed by Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity, as a result of activation of NR2B-containing N-methyl-D-aspartate subtype of glutamate receptors (NMDARs) during ischemia. Furthermore, NR2B-specific antagonist, CaMKII inhibitor, or overexpression of mutated form of ASIC1a with Ser478 or Ser479 replaced by alanine (ASICla-S478A, ASIC1a-S479A) in cultured hippocampal neurons prevented ischemia-induced enhancement of ASIC currents, cytoplasmic Ca2+ elevation, as well as neuronal death. Thus, NMDAR-CaMKII cascade is functionally coupled to ASICs and contributes to acidotoxicity during ischemia. Specific blockade of NMDAR/CaMKII-ASIC coupling may reduce neuronal death after ischemia and other pathological conditions involving excessive glutamate release and acidosis.
Resumo:
The subiculum, which is the primary target of CA1 pyramidal neurons and sending efferent fibres to many brain regions, serves as a hippocampal interface in the neural information processes between hippocampal formation and neocortex. Long-term depression (LTD) is extensively studied in the hippocampus, but not at the CA1-subicular synaptic transmission. Using whole-cell EPSC recordings in the brain slices of young rats, we demonstrated that the pairing protocols of low frequency stimulation (LFS) at 3 Hz and postsynaptic depolarization of -50 mVelicited a reliable LTD in the subiculum. The LTD did not cause the changes of the paired-pulse ratio of EPSC. Furthermore, it did not depend on either NMDA receptors or voltage-gated calcium channels (VGCCs). Bath application of the G-protein coupled muscarinic acetylcholine receptors (mAChRs) antagonists, atropine or scopolamine, blocked the LTD, suggesting that mAChRs are involved in the LTD. It was also completely blocked by either the Ca2+ chelator BAPTA or the G-protein inhibitor GDP-beta-S in the intracellular solution. This type of LTD in the subiculum may play a particular role in the neural information processing between the hippocampus and neocortex. (c) 2005 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.
Resumo:
, EDTA 1 391 KUg - 1 ,,1 2 5 mmolL - 1Ca2 + Mg2 + Mn2 + ,1 2 mmolL - 1Zn2 + Co2 + ,5 mmolL - 1Zn2 + Co2 + ,Cu2 + 1 2 5 mmolL - 1 , EDTA , EDTA
Resumo:
,,,,Morris;Ca2+,,,(p<0.05,p<0.01),(p<0.05,p<0.01);(p<0.05,p<0.01);Ca2+(p<0.05,p<0.01),,,,Ca2+
Resumo:
(batch method):(0.02mmolL-1)Ca2+Mg2+Na+1.0mmolL-18mmolL-1,Ca2+,Mg2+,K+,Na+,Si,Al3+Ca2+Mg2+,Na+K+
