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101.
102.
Dermorphins, Opioid Peptides from Amphibian Skin, Act on Opioid Receptors of Mouse Neuroblastoma x Rat Glioma Hybrid Cells 总被引:1,自引:0,他引:1
Thomas Glaser Karin Hübner Roberto de Castiglione Bernd Hamprecht 《Journal of neurochemistry》1981,37(6):1613-1617
Dermorphin and its Hyp6 analogue are opiate-like heptapeptides originally discovered in frog skin and characterized by the presence of a D-Ala2 residue in their sequence. They were assayed for their capacity to compete with [3H]Leu-enkephalin for binding to opioid receptors in membranes of neuroblastoma x glioma hybrid cells. In the presence of 7 nM-[3H]Leu-enkephalin, the concentrations at which they caused 50% inhibition of [3H]enkephalin binding (IC50 values) are 0.1 micro M and 0.3 micro M, respectively. In contrast, the synthetic L-Ala2-dermorphin shows very low affinity for the opioid receptors. In addition, like other opioid peptides, dermorphin and hyp6-dermorphin inhibit the elevation by prostaglandin E1 (PGE1) of the level of adenosine 3':5'-cyclic monophosphate (cyclic AMP) (IC50 values 0.2 micro M and 0.4 micro M, respectively). The inhibition is prevented by the opiate antagonist naloxone, L-Ala2-dermorphin is at least three orders of magnitude less potent in inhibiting the PGE1-evoked increase in the level of cyclic AMP. The results show that peptides with an amino acid sequence quite different from that of the enkephalins can bind to opioid receptors of the hybrid cells. 相似文献
103.
Csepeggi C Jiang M Kojima F Crofford LJ Frolov A 《The Journal of biological chemistry》2011,286(3):2078-2087
A growing body of evidence points toward activated fibroblasts, also known as myofibroblasts, as one of the leading mediators in several major human pathologies including proliferative fibrotic disorders, invasive tumor growth, rheumatoid arthritis, and atherosclerosis. Niemann-Pick Type C2 (NPC2) protein has been recently identified as a product of the second gene in NPC disease. It encodes ubiquitous, highly conserved, secretory protein with the poorly defined function. Here we show that NPC2 deficiency in human fibroblasts confers their activation. The activation phenomenon was not limited to fibroblasts as it was also observed in aortic smooth muscle cells upon silencing NPC2 gene by siRNA. More importantly, activated synovial fibroblasts isolated from patients with rheumatoid arthritis were also identified as NPC2-deficient at both the NPC2 mRNA and protein levels. The molecular mechanism responsible for activation of NPC2-null cells was shown to be a sustained phosphorylation of ERK 1/2 mitogen-activated protein kinase (MAPK), which fulfills both the sufficient and necessary fibroblast activation criteria. All of these findings highlight a novel mechanism where NPC2 by negatively regulating ERK 1/2 MAPK phosphorylation may efficiently suppress development of maladaptive tissue remodeling and inflammation. 相似文献
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105.
J. Wiegel 《Archives of microbiology》1985,142(2):194-199
The -isopropylmalate synthase of the chemolithoautotrophic Alcaligenes eutrophus H16 is apparently a soluble enzyme but is strongly adsorbed to cell particles in ruptured cell suspensions. This was not observed with -acetohydroxy acid synthase or threonine deaminase. The formation of these regulatory enzymes of the branched chain amino acid biosynthesis pathway generally decreased with decreased growth rates. The addition of 5 mM valine plus isoleucine with and without 5 mM threonine caused a 6.6- and a 4-fold increase, respectively, in the formation of active -isopropylmalate synthase, but caused a strong decrease in the -actohydroxy acid synthase. The level of active -isopropylmalate synthase is apparently regulated by the level of leucine; whereas, the level of the -acetohydroxy acid synthase and threonine deaminase is influenced by the presence of several amino acids. A catabolic threonine deaminase was not encountered.Abbreviations IRS
-Isopropylamalate
- AHA
-acetohydroxy acid
- TDA
throninedeaminase
This paper is dedicated to Professor H. G. Schlegel, University Göttingen, on the occasion of his 60th birthday. I am grateful to a great teacher and scientist, who in his unique way stimulated enthusiasm and fascination in microbiology in his students throughout the years 相似文献
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中国是全球生物多样性最丰富的国家之一.最近40年,中国的植物多样性保护取得了巨大成就,实施了多项政策和法律,尤其是《野生植物保护条例》和《国家重点保护野生植物名录》先后颁布,奠定了中国植物保护的法律和政策框架,就地保护和迁地保护网络基本形成.但与生态文明建设的要求相比,野生植物保护依然存在许多不足.本文系统回顾了中国野... 相似文献
108.
Page TH D'Souza Z Nakanishi S Serikawa T Pusey CD Aitman TJ Cook HT Behmoaras J 《The Journal of biological chemistry》2012,287(8):5710-5719
Crescentic glomerulonephritis (Crgn) is a complex disease where the initial insult is often the glomerular deposition of antibodies against intrinsic or deposited antigens in the glomerulus. The role of Fc receptors in the induction and progression of Crgn is increasingly recognized, and our previous studies have shown that copy number variation in Fcgr3 partially explains the genetic susceptibility of the Wistar-Kyoto (WKY) rat to nephrotoxic nephritis, a rat model of Crgn. The Fcgr3-related sequence (Fcgr3-rs) is a novel rat-specific Fc receptor with a cytoplasmic domain 6 amino acids longer than its paralogue, Fcgr3. The Fcgr3-rs gene is deleted from the WKY rat genome, and this deletion is associated with enhanced macrophage activity in this strain. Here, we investigated the mechanism by which the deletion of Fcgr3-rs in the WKY strain leads to increased macrophage activation. By lentivirus-mediated gene delivery, we generated stably transduced U937 cells expressing either Fcgr3-rs or Fcgr3. In these cells, which lack endogenous Fcgr3 receptors, we show that Fcgr3-rs interacts with the common Fc-γ chain but that Fc receptor-mediated phagocytosis and signaling are defective. Furthermore, in primary macrophages, expression of Fcgr3-rs inhibits Fc receptor-mediated functions, because WKY bone marrow-derived macrophages transduced with Fcgr3-rs had significantly reduced phagocytic activity. This inhibitory effect on phagocytosis was mediated by the novel cytoplasmic domain of Fcgr3-rs. These results suggest that Fcgr3-rs may act to inhibit Fcgr3-mediated signaling and phagocytosis and could be considered as a novel mechanism in the modulation of Fc receptor-mediated cell activation in autoimmune diseases. 相似文献
109.
Islam MR Jimenez T Pelham C Rodova M Puri S Magenheimer BS Maser RL Widmann C Calvet JP 《The Journal of biological chemistry》2010,285(50):38818-38831
110.