共查询到20条相似文献,搜索用时 31 毫秒
1.
Moo Woong Kim Su-Min Ko Jeong-Yoon Kim Jung-Hoon Sohn Eui-Sung Choi Hyun Ah Kang Sang-Ki Rhee 《Biotechnology and Bioprocess Engineering》2000,5(4):234-241
TheSaccharomyces cerevisiae PMR1 gene encodes a Ca2+-ATPase localized in the Golgi. We have investigated the effects ofPMR1 disruption inS. cerevisiae on the glycosylation and secretion of three heterologous glycoproteins, human α1-antitrypsin (α1-AT), human antithrombin III (ATHIII), andAspergillus niger glucose oxidase (GOD). Thepmr1 null mutant strain secreted larger amounts of ATHIII and GOD proteins per a unit cell mass than the wild type strain. Despite
a lower growth rate of thepmr1 mutant, two-fold higher level of human ATHIII was detected in the culture supernatant from thepmr1 mutant compared to that of the wild-type strain. Thepmr1 mutant strain secreted α1-AT and the GOD proteins mostly as core-glycosylated forms, in contrast to the hyperglycosylated proteins secreted in the
wild-type strain. Furthermore, the core-glycosylated forms secreted in thepmr1 mutant migrated slightly faster on SDS-PAGE than those secreted in themnn9 deletion mutant and the wild type strains. Analysis of the recombinant GOD with anti-α1,3-mannose antibody revealed that
GOD secreted in thepmr1 mutant did not have terminal α1,3-linked mannoses unlike those secreted in themnn9 mutant and the wild type strains. The present results indicate that thepmr1 mutant, with the super-secretion phenotype, is useful as a host system to produce recombinant glycoproteins lacking high-mannose
outer chains. 相似文献
2.
Heather A. E. Benson Rima Caccetta Yan Chen Philip Kearns Istvan Toth 《International journal of peptide research and therapeutics》2003,10(5-6):615-620
Skin penetration of the tetrapeptide Ac-Ala-Ala-Pro-Val-NH2 was assessed. This peptide sequence fits the P-P1 subsites of elastase and inhibits human neutrophil elastase competitively. Consequently this peptide may be therapeutically
useful in a variety of inflammatory disorders, including psoriasis, in which elevated levels of human neutrophil elastase
have been reported. Peptide penetration was assessed across whole human skin, whole skin with the stratum corneum removed by tape stripping and epidermis, which had been removed from the dermis by heat separation. The influence of 75 aqueous
ethanol as a potential penetration enhancer of the tetrapeptide across epidermis was also assessed. The tetrapeptide did not
penetrate whole human skin or epidermis, even under the influence of 75 aqueous ethanol. However, when the stratum corneum was removed tetrapeptide flux of 73.39 μg cm2 h−1 was achieved. The study demonstrates that the stratum corneum is the main barrier to tetrapeptide skin penetration and must be overcome if therapeutically relevant amounts of tetrapeptide
are to be delivered to the skin. 相似文献
3.
Hiroaki Kataoka Kazuki Nabeshima Naoto Komada Masashi Koono 《Virchows Archiv. B, Cell pathology including molecular pathology》1989,57(1):157-165
Two new human cell lines, RCM-1 and CoCM-1, have been established from primary colorectal adenocarcinomas. Both cell lines
were unique in that the cultures secreted trypsin inhibitors in vitro. The activities of these inhibitors were accumulated
in serum-free media of both cell lines over a period of several days. Two inhibitors (PI-1 and PI-2) were isolated from serum-free
conditioned medium in which RCM-1 was grown by anion-exchange and gel filtration high-performance liquid chromatography. PI-1
inhibited trypsin and chymotrypsin strongly, and pancreatic elastase weakly. Its molecular weight was about 57 kilodaltons
(Kd) as determined by gel filtration chromatography. It cross-reacted with the antiserum elicited against human α1-antitrypsin in double immunodiffusion. PI-1 corresponding to α1
- antitrypsin was also demonstrated immunohistochemically in both cell lines. PI-2 inhibited trypsin strongly, and chymotrypsin,
kallikrein and plasmin weakly. It had higher molecular weight (200–300 Kd) than that of PI-1, and did not crossreact with
antisera against human α1-antitrypsin, α2-macroglobulin, α1-antichymotrypsin, α2-plasmin inhibitor, inter-α-trypsin inhibitor and urinary trypsin inhibitor. RCM-1 and CoCM-1 are the first colorectal adenocarcinoma
cell lines that secrete functionally active trypsin inhibitors, including α1-antitrypsin in vitro, and are useful for the study of tumor-cell derived proteinase inhibitors. 相似文献
4.
Gypenoside XLIX isolated from Gynostemma pentaphyllum inhibits nuclear factor-kappaB activation via a PPAR-alpha-dependent pathway 总被引:2,自引:0,他引:2
Huang TH Li Y Razmovski-Naumovski V Tran VH Li GQ Duke CC Roufogalis BD 《Journal of biomedical science》2006,13(4):535-548
Summary Nuclear factor (NF)-κB is important in the generation of inflammation. Besides regulating lipid metabolism, peroxisome proliferator-activated receptor (PPAR)-α activators also reduce NF-κB activation to terminate activation of inflammatory pathways. Gynostemma pentaphyllum (GP) has been used to treat various inflammatory diseases and hyperlipidemia. Here, we demonstrate that GP extract and one of its main components, Gypenoside XLIX (Gyp-XLIX) inhibited LPS-induced NF-κB activation in murine macrophages. Furthermore, Gyp-XLIX restored the LPS- and TNF-α-induced decrease in cytosolic I-κBα protein expression and inhibited the translocation of NF-κB(p65) to the nucleus in THP-1 monocyte and HUVEC cells. The inhibition of LPS- and TNF-α-induced NF-κB luciferase activity in macrophages was abolished by MK-886, a selective PPAR-α antagonist. GP extract and Gyp-XLIX (EC50: 10.1 μM) enhanced PPAR-α luciferase activity in HEK293 cells transfected with the tK-PPREx3-Luc reporter plasmid and expression vectors for PPAR-α. Additionally, Gyp-XLIX specifically enhanced PPAR-α mRNA and protein expression in THP-1-derived macrophage cells. The selectivity of Gyp-XLIX for PPAR-α was demonstrated by the activation of only PPAR-α in HEK293 cells transfected with expression vectors for PPAR-α, PPAR-β/δ or PPAR-γ1 plasmids and in THP-1-derived macrophage naturally expressing all three PPAR isoforms. The present study demonstrates that Gyp-XLIX, a naturally occurring gynosaponin, inhibits NF-κB activation via a PPAR-α-dependent pathway.Tom Hsun-Wei Huang and Yuhao Li contributed equally. 相似文献
5.
Integrins, a family of transmembrane heterodimeric polypeptides, mediate various biological responses including cell adhesion
and migration. In this report, we show that sphingosine-1-phosphate (S1P) activates integrin αvβ3 in endothelial cells (ECs) via the sphingosine-1-phosphate receptor subtype 1 (S1P1)-mediated signaling pathway. S1P treatment
results in the activation of integrin αvβ3 in the lamellipodia region of ECs, suggesting that integrin αvβ3 plays a critical role in the S1P-stimulated chemotactic response of ECs. Indeed, S1P treatment induces the association of
focal adhesion kinase (FAK) and cytoskeletal proteins with integrin αvβ3, the ligation of αv and β3 subunits, as well as enhances endothelial migration on vitronectin-coated substrata. Knockdown endothelial S1P1 receptor,
treatments with pertussis toxin or dominant-negative-Rho family GTPases abrogates the S1P-induced integrin αvβ3 activation in ECs. Consequently, these treatments markedly inhibit the S1P-induced endothelial migratory response on vitronectin-coated
substrata. Collectively, these data indicate that the S1P-mediated signaling via the S1P1/Gi/Rho GTPases pathway activates integrin αvβ3, which is indispensable for S1P-stimulated chemotactic response of ECs. 相似文献
6.
Marta Grófová Erik Larsson Allan Bengtsson Jozef Bizik Bengt Westermark Jan Pontén 《In vitro cellular & developmental biology. Plant》1988,24(5):369-372
Summary The presence ofα
2-macroglobulin was detected with the avidin-biotin technique in more than 20-yr-old paraffin blocks from human sarcomas.α
2M was found mainly in the cytoplasm of the tumor cells, and almost all tumor cells were positive. This serum glycoprotein,
which is a major plasma proteinase inhibitor with a wide specificity, was also shown to be synthesized and secreted by all
three cell lines derived from primary sarcomas but was not detected in cultures of the autologous skin fibroblasts. For the
detection ofα
2M in situ and in vitro an antiserum to tumor-associatedα
2-macroglobulin was used.
Our work was supported by grant no. 55-B86-21XB, from the Swedish Cancer Society. 相似文献
7.
Katherine E. S. Locock Graham A. R. Johnston Robin D. Allan 《Neurochemical research》2009,34(10):1698-1703
The incorporation of extra binding groups onto known ligands is a powerful tool for the development of more potent and selective
agents at target sites such as the GABA receptors. In the present work we have attempted to build on the activity of the know
potent GABAA agonist 4-ACP-3-CA and its cis and trans saturated analogues CACP and TACP. We have investigated reactions to add thiol substituents to the α,β-unsaturated system
of 4-ACP-3-CA. The reaction was successful with a limited number of thiols but gave products of mixed stereochemistry. The
resultant thioether amino acids were screened for activity at human recombinant α1β2 γ2L GABAA receptors. The most interesting derivative was the benzylthioether which acted as an antagonist with an IC50 of 42 μM for the inhibition of a GABA EC50 dose (50 μM). This study has shown that GABA analogues derived by thiol addition to 4-aminocyclopent-1-enecarboxylic acid display interesting antagonist activity at the α1β2γ2L GABAA receptor.
Special issue article in honour of Dr. Graham Johnston. 相似文献
8.
The excitation energy transfer between carotenoid and chlorophyll (Chl) in the cytochrome b
6
f complex from Bryopsis corticulans (B. corticulans), in which the carotenoid is 9-cis-α-carotene, was investigated by means of fluorescence excitation and sub-microsecond time-resolved absorption spectroscopies. The presence of efficient singlet excitation transfer from α-carotene to Chl a was found with an overall efficiency as high as ∼
∼24%, meanwhile the Chl a-to-α-carotene triplet excitation transfer was also evidenced. Circular dichroism spectroscopy showed that α-carotene molecule existed in an asymmetric environment and Chl a molecule had a certain orientation in this complex.Bin-Xing Li and Ping Zuo contributed equally to this work. 相似文献
9.
Jing Wu Min-Chen Wu Lian-Fen Zhang Jian-Yong Lei Lei Feng Jian Jin 《Journal of biosciences》2009,34(2):213-220
ADAM15 plays an important role in tumour development by interacting with integrins. In this study, we investigated the target
peptides of the ADAM15 disintegrin domain. First, we successfully produced the recombinant human ADAM15 disintegrin domain
(RADD) that could inhibit melanoma cell adhesion by using Escherichia coli. Second, four specific binding peptides (peptides A, B, C, and D) were selected using a phage display 12-mer peptide library.
The screening protocol involved 4 rounds of positive panning on RADD and 2 rounds of subtractive selection with streptavidin.
By using the BLAST software and a relevant protein database, integrin α
ν
β
3 was found to be homologous to peptide A. Synthetic peptide A had a highly inhibitory effect on RADD-integrin α
v
β
3 binding. The results demonstrate the potential application of short peptides for disrupting high-affinity ADAM-integrin interactions. 相似文献
10.
Sonya Cressman Ying Sun E. Jane Maxwell Ning Fang David D. Y. Chen Pieter R. Cullis 《International journal of peptide research and therapeutics》2009,15(1):49-59
The cyclic peptide, cRGDf[N(me)]V, binds to the α
v
β
3 integrin and can disrupt binding of the integrin to its natural ligands in the extracellular matrix. In this work, the ability
of a water-soluble, fluorescently labeled variant of the RGD-containing peptide (cRGDfK-488) to bind to integrins on human
umbilical vascular endothelial cells (HUVEC) and subsequently undergo endocytosis was characterized. This information was
compared to the binding and uptake properties of an α
v
β
3 integrin-specific monoclonal antibody, LM609X. The specificity of the RGD-containing peptide is assessed by comparison with
control peptide that does not bind to the α
v
β
3 integrin, cRADfK-488. Using a high purity construct, it is shown that the RGD ligand exhibits dissociation constants in the
micromolar range whereas LM609X exhibits dissociation constants in the nanomolar range. However, the RGD ligand showed greater
uptake following incubation at temperatures which permit endocytosis. A 7.4-fold increase in uptake of the RGD peptide was
observed following a 1 h incubation with HUVEC at 37°C (an endocytosis permissive temperature), as compared to that at 4°C
(an endocytosis prohibitive temperature). In contrast, only a 1.9-fold increase in cell-associated fluorescence was observed
for similar incubations with LM609X. Results from fluorescence microscopy supports the notion that the RGD peptide is rapidly
endocytosed at 37°C as compared to LM609X. These results are discussed with regard to previous work indicating that RGD ligands
enter cells by integrin-independent pathways. These studies provide well-controlled measures of how RGD ligands stimulate
endocytosis. This may be of considerable interest for intracellular delivery of ligand-associated drugs in anti-angiogenic
applications. 相似文献
11.
Mylonas I Schiessl B Jeschke U Vogl J Makrigiannakis A Kuhn C Kunze S Schulze S Kainer F Friese K 《Journal of molecular histology》2006,37(1-2):43-52
During human pregnancy the placenta produces a variety of proteins like steroid hormones and their receptors that are responsible for the establishment and ongoing of the feto-placental unit. Inhibins are dimeric glycoproteins, composed of an α-subunit and one of two possible β-subunits (β
A or β
B). Aims of the present study were the determination of the frequency and tissue distribution patterns of the inhibin/activin subunits in human placental tissue of normal pregnancies and pregnancies complicated with fetal growth restriction (IUGR). Slides of paraffin embedded placental tissue were obtained after delivery from patients diagnosed with IUGR (n = 6) and normal term placentas (n = 8). Tissue samples were fixed and incubated with monoclonal antibodies inhibin/activin-subunits -α, -β
A, -β
B. Intensity of immunohistochemical reaction on the slides was analysed using a semi-quantitative score and statistical analysis was performed (P<0.05). A significant lower expression of the inhibin-α subunit in IUGR extravillous trophoblast compared to normal pregnancies was observed, while the inhibin-α immunostaining was significantly upregulated in syncytiotrophoblast. Additionally, a significant down-regulation of inhibin-β
B subunit in extravillous trophoblast cells in IUGR syncytiotrophoblast cells was demonstrated. A co-localisation of inhibin-α and the β-subunits was also observed, suggesting a production and secretion of intact inhibin A and inhibin B. Although the precise role of these inhibin/activin subunits in human placenta and IUGR pregnancies is still unclear, they could be involved in autocrine/paracrine signalling, contributing to several aspects like angiogenesis and tissue remodelling. 相似文献
12.
Chen SP Wu JL Su YC Hong JR 《Apoptosis : an international journal on programmed cell death》2007,12(6):1043-1060
Nervous necrosis virus (NNV)-induced, host cell apoptosis mediates secondary necrosis by an ill-understood process. In this
study, redspotted grouper nervous necrosis virus (RGNNV) is shown to induce mitochondria-mediated necrotic cell death in GL-av
cells (fish cells) via cytochrome c release, and anti-apoptotic proteins are shown to protect these cells from death. Western blots revealed that cytochrome
c release coincided with disruption of mitochondrial ultrastructure and preceded necrosis, but did not correlate with caspases
activation. To identify the mediator(s) of this necrotic process, a protein synthesis inhibitor (cycloheximide; CHX; 0.33 μg/ml)
was used to block cytochrome c release as well as PS exposure and mitochondrial membrane permeability transition pore (MMP) loss. CHX (0.33 μg/ml) completely
blocked viral protein B2 expression, and partly blocked protein A, protein α, and a pro-apoptotic death protein (Bad) expression.
Overexpression of B2 gene increased necrotic-like cell death up to 30% at 48 h post-transfection, suggesting that newly synthesized protein (B2)
may be involved in this necrotic process. Finally, necrotic death was prevented by overexpression of Bcl-2 family proteins,
zfBcl-xL and xfMcl-1a. Thus, new protein synthesis and release of cytochrome c are required for RGNNV-induced necrotic cell death, which can be blocked by anti-apoptotic Bcl-2 members.
J.-L. Wu and J.-R. Hong contributed equally to the research. 相似文献
13.
14.
P2X1 receptors, the major subtype of P2X receptors in the vascular smooth muscle, are essential for α,β-methylene adenosine 5′-triphosphate
(α,β-MeATP)-induced vasoconstriction. However, relative physiological significance of P2X1 receptor-regulated vasoconstriction in the different types of arteries in the rat is not clear as compared with α1-adrenoceptor-regulated vasoconstriction. In the present study, we found that vasoconstrictive responses to noncumulative
administration of α,β-MeATP in the rat isolated mesenteric arteries were significantly smaller than those to single concentration
administration of α,β-MeATP. Therefore, we firstly reported the characteristic of α,β-MeATP-regulated vasoconstrictions in
rat tail, internal carotid, pulmonary, mesenteric arteries, and aorta using single concentration administration of α,β-MeATP.
The rank order of maximal vasoconstrictions for α,β-MeATP (E
max·α,β-MeATP) was the same as that of maximal vasoconstrictions for noradrenaline (E
max·NA) in the internal carotid, pulmonary, mesenteric arteries, and aorta. Moreover, the value of (E
max·α,β-MeATP/E
max·KCl)/(E
max·NA/E
max·KCl) was 0.4 in each of the four arteries, but it was 0.8 in the tail artery. In conclusion, P2X1 receptor-mediated vasoconstrictions are equally important in rat internal carotid, pulmonary, mesenteric arteries, and aorta,
but much greater in the tail artery, suggesting its special role in physiological function. 相似文献
15.
Peroxisome proliferator-activated receptor gamma (PPARγ) activation by its ligands reportedly inhibits monocyte function.
However, because the concentrations of PPARγ ligands used in previous studies were higher than typically expected to activate
PPARγ, we clarified whether PPARγ ligands influence monocyte function and cell viability of the human monocyte cell line THP-1.
We determined tumor necrosis factor-alpha (TNF-α) release as a monocyte function and cell viability using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium
bromide. Both troglitazone and 15-deoxy-Δ12,14-prostaglandin J2 (15-d-PGJ2) seemed to inhibit phorbol ester-induced TNF-α release from THP-1 cells. On the other hand, neither pioglitazone
nor rosiglitazone inhibited phorbol ester-induced TNF-α release. Because the cytotoxicity of troglitazone and 15-d-PGJ2 was
significantly (p<0.05, Tukey–Kramer) stronger than that of pioglitazone and rosiglitazone, the inhibition of TNF-α release seemed to parallel
the lack of cell viability. We concluded that PPARγ ligands did not directly inhibit TNF-α release in THP-1 cells.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
Begoña Gómez-Miranda Alicia Prieto Juan Antonio Leal Oussama Ahrazem Jesús Jiménez-Barbero Manuel Bernabé 《Glycoconjugate journal》2003,20(4):239-246
The alkali extractable and water-soluble cell wall polysaccharides F1SS from Aspergillus wentii and Chaetosartorya chrysella have been studied by methylation analysis, 1D- and 2D-NMR, and MALDI-TOF analysis. Their structures are almost identical,
corresponding to the following repeating unit:
[→ 3)-β-D-Galf-(1 → 5)-β-D-Galf-(1 →]
n
→ mannan core.
The structure of this galactofuranose side chain differs from that found in the pathogenic fungus Aspergillus fumigatus, in other Aspergillii and members of Trichocomaceae:
[→ 5)-β-D-Galf-(1 →]
n
→ mannan core.
The mannan cores have also been investigated, and are constituted by a (1 → 6)-α-mannan backbone, substituted at positions
2 by chains from 1 to 7 residues of (1 → 2) linked α-mannopyranoses. Published in 2004.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Summary In this study, the variety of sugar residues in the gut glycoconjugates of Triturus carnifex (Amphibia, Caudata) are investigated by carbohydrate conventional histochemistry and lectin histochemistry. The oesophageal
surface mucous cells contained acidic glycoconjugates, with residues of GalNAc, Gal β1,3 GalNAc and (GlcNAc β1,4)
n
oligomers. The gastric surface cells mainly produced neutral glycoproteins with residues of fucose, Gal β1-3 GalNAc, Gal-αGal,
and (GlcNAc β1,4)
n
oligomers in N- and O-linked glycans, as the glandular mucous neck cells, with residues of mannose/glucose, GalNAc, Gal β1,3
GalNAc, (GlcNAc β1,4)
n
oligomers and fucose linked α1,6 or terminal α1,3 or α1,4 in O-linked glycans. The oxynticopeptic tubulo-vesicular system
contained neutral glycoproteins with N- and O-linked glycans with residues of Gal-αGal, Gal β1-3 GalNAc and (GlcNAc β1,4)
n
oligomers; Fuc linked α1,2 to Gal, α1,3 to GlcNAc in (poly)lactosamine chains and α1,6 to GlcNAc in N-linked glycans. Most
of these glycoproteins probably corresponds to the H+K+-ATPase β-subunit. The intestinal goblet cells contained acidic glycoconjugates, with residues of GalNAc, mannose/ glucose,
(GlcNAc β1,4)
n
oligomers and fucose linked α1,2 to Gal in O-linked oligosaccharides. The different composition of the mucus in the digestive
tracts may be correlated with its different functions. In fact the presence of abundant sulphation of glycoconjugates, mainly
in the oesophagus and intestine, probably confers resistance to bacterial enzymatic degradation of the mucus barrier. 相似文献
18.
19.
The differences in pigment levels, photosynthetic activity and the chlorophyll fluorescence decrease ratio R
Fd (as indicator of photosynthetic rates) of green sun and shade leaves of three broadleaf trees (Platanus acerifolia Willd., Populus alba L., Tilia cordata Mill.) were compared. Sun leaves were characterized by higher levels of total chlorophylls a + b and total carotenoids x + c as well as higher values for the weight ratio chlorophyll (Chl) a/b (sun leaves 3.23–3.45; shade leaves: 2.74–2.81), and lower values for the ratio chlorophylls to carotenoids (a + b)/(x + c) (with 4.44–4.70 in sun leaves and 5.04–5.72 in shade leaves). Sun leaves exhibited higher photosynthetic rates P
N on a leaf area basis (mean of 9.1–10.1 μmol CO2 m−2 s−1) and Chl basis, which correlated well with the higher values of stomatal conductance G
s (range 105–180 mmol m−2 s−1), as compared to shade leaves (G
s range 25–77 mmol m−2 s−1; P
N: 3.2–3.7 μmol CO2 m−2 s−1). The higher photosynthetic rates could also be detected via imaging the Chl fluorescence decrease ratio R
Fd, which possessed higher values in sun leaves (2.8–3.0) as compared to shade leaves (1.4–1.8). In addition, via R
Fd images it was shown that the photosynthetic activity of the leaves of all trees exhibits a large heterogeneity across the
leaf area, and in general to a higher extent in sun leaves than in shade leaves. 相似文献
20.
We studied the effects of trace elements, Mn, Mo, and Si, on vasoconstriction induced by norepinephrine (NE) or electrical
field stimulation in isolated porcine right coronary arteries. α1-Adrenoceptor (AR) antagonist prazosin dose-despondently suppressed vasoconstriction in response to NE or field stimulation
indicating an α1-AR mediated response. Mn, Mo, and Si at 0.3-3 μmol/L dosedespondently inhibited NE mediated contraction (allp < 0.05). In contrast, Mn, Mo, and Si at the same concentrations (0.3-3 μmol/L) enhanced the maximal contractile response to
field stimulation in a dose-dependent manner (allp < 0.05), but these elements at 10 μmol/L suppressed the vasoconstrictive response. The results indicate that in porcine right
coronary arteries, the α1-AR-mediated vasoconstriction by NE or electrical field stimulation was affected differently by micromolar concentrations
of Mn, Mo, and Si and that the elements might facilitate NE release presynaptically but inhibit the contractile response postsynaptically. 相似文献