排序方式: 共有44条查询结果,搜索用时 31 毫秒
1.
E I Emelyanenko M I Shakhparonov N N Modyanov 《Biochemical and biophysical research communications》1985,126(1):214-219
Water-soluble and membrane-bound calmodulin-binding polypeptides formed upon limited proteolysis of erythrocyte ghosts were isolated by means of affinity chromatography. Immune blotting revealed that all isolated fragments originated from Ca2+-ATPase. Among the fragments obtained those having formed an acylphosphate intermediate were identified. The N-terminal residue of purified intact Ca2+-ATPase was shown to be blocked (probably acylated). 相似文献
2.
Arkblad EL Egorov M Shakhparonov M Romanova L Polzikov M Rydström J 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2002,133(1):13-21
Proton-translocating nicotinamide nucleotide transhydrogenase is located in the mitochondrial inner membrane and catalyzes the reduction of NADP(+) by NADH to NADPH and NAD(+). The present investigation describes the expression of the transhydrogenase gene in various mouse organs, subsections of the human brain and Caenorhabditis elegans. In the mouse, the expression was highest in heart tissue (100%) followed by kidney (64%), testis (52%), adrenal gland (41%), liver (35%), pancreas (34%), bladder (26%), lung (25%), ovary (21%) and brain (14%). The expression in brain tissue was further investigated in the human brain which showed a distribution that apparently varied as a function of neuronal density, a result that was supported by estimations of expression in C. elegans using Green Fluorescent Protein (GFP) controlled by the transhydrogenase promoter. GFP-expressing C. elegans lines showed a clear concentration of fluorescence to the gut, the pharyngeal-intestinal valve and certain neurons. It is concluded that the transhydrogenase gene is expressed to various extents in all cell types in mouse, human and C. elegans. 相似文献
3.
Freya L. Sheeran Jan Rydström Mikhail I. Shakhparonov Nikolay B. Pestov Salvatore Pepe 《BBA》2010,1797(6-7):1138-1148
Although the functional role of nicotinamide nucleotide transhydrogenase (Nnt) remains to be fully elucidated, there is strong evidence that Nnt plays a critical part in mitochondrial metabolism by maintaining a high NADPH-dependant GSH/GSSG ratio, and thus the control of cellular oxidative stress. Using real-time PCR, spectrophotometric and western blotting techniques, we sought to determine the presence, abundance and activity level of Nnt in human heart tissues and to discern whether these are altered in chronic severe heart failure. Left ventricular levels of the NNT gene and protein expression did not differ significantly between the non-failing donor (NF) and heart failure (HF) group. Notably, compared to NF, Nnt activity rates in the HF group were 18% lower, which coincided with significantly higher levels of oxidized glutathione, lower glutathione reductase activity, lower NADPH and a lower GSH/GSSG ratio. In the failing human heart a partial loss of Nnt activity adversely impacts NADPH-dependent enzymes and the capacity to maintain membrane potential, thus contributing to a decline in bioenergetic capacity, redox regulation and antioxidant defense, exacerbating oxidative damage to cellular proteins. 相似文献
4.
Slizhikova DK Zinov'eva MV Kuz'min DV Snezhkov EB Shakhparonov MI Dmitriev RI Antipova NV Zavalova LL Sverdlov ED 《Molekuliarnaia biologiia》2007,41(4):659-665
Secretory polymeric immunoglobulins (IgA dimers and IgM pentamers) are unique in that, apart from L- and H-chains, they contain J-chains responsible for their oligomerization. These antibodies are part of the local adaptive immune system acting on mucosa membranes of the respiratory and digestive systems as the first protection barrier to potential infectious agents. Secretory polymeric immunoglobulins are produced by highly specific B-cells and actively transported to the surface of mucosa membrane through epithelium cells. Therefore, their synthesis and J-chain content are dependent upon epithelium translocation function and condition that are markedly affected by tumorous transformation. Here, we used RT-PCR and immunoblotting to study of the J-chain content and its mRNA expression level in normal and tumorous tissues in lung squamous cell cancer and adenocarcinoma at various stages of disease progression. 相似文献
5.
6.
7.
Mitochondrial transhydrogenase catalyzes the reaction; Hout+ + NADP+ + NADH = NAD+ + NADPH + Hin+. The maintenance of the NADPH pool increases the mitochondrial antioxidant potential. Therefore, according to the commonly
adopted free radical theory of aging, ablation of the transhydrogenase gene should reduce the life span. However, contrary
to this reasoning, the life span of Caenorhabditis elegans nematodes with null mutations in the gene does not differ from that in wild-type worms. This fact indicates that free radical
damage of mitochondria is not associated with aging. Meta analysis of data on the life span in mice possessing a spontaneous
mutation in the transhydrogenase gene shows that a lack of this enzyme does not accelerate aging in mammals either. The heart
is the tissue with the highest transhydrogenase production rate, and it is likely that this enzyme contributes to the protection
of cardiac myocytes from oxidative stress. 相似文献
8.
Pavlyukov MS Antipova NV Balashova MV Vinogradova TV Kopantzev EP Shakhparonov MI 《The Journal of biological chemistry》2011,286(26):23296-23307
Survivin was initially described as an inhibitor of apoptosis and attracted growing attention as one of the most tumor-specific genes in the human genome and a promising target for cancer therapy. Lately, it has been shown that survivin is a multifunctional protein that takes part in several crucial cell processes. At first, it was supposed that survivin functions only as a homodimer, but now data indicate that many processes require monomeric survivin. Moreover, recent studies reveal a special mechanism regulating the balance between monomeric and dimeric forms of the protein. In this paper we studied the mutant form of survivin that was unable to dimerize and investigated its role in apoptosis. We showed that survivin monomer interacts with Smac/DIABLO and X-linked inhibitor of apoptosis protein (XIAP) both in vitro and in vivo. Due to this feature, it protects cells from caspase-dependent apoptosis even more efficiently than the wild-type survivin. We also identified that mutant monomeric survivin prevents apoptosis-inducing factor release from the mitochondrial intermembrane space, protecting human fibrosarcoma HT1080 cells from caspase-independent apoptosis. On the other hand, our results indicate that only wild-type survivin, but not the monomer mutant form, enhances tubulin stability in cells. These findings suggest that survivin partly performs its functions as a monomer and partly as a dimer. The mechanism of dimer-monomer balance regulation may also work as a "switcher" between survivin functions and thereby explain remarkable functional diversities of this protein. 相似文献
9.
M S Feschenko E I Zvaritch F Hofmann M I Shakhparonov N N Modyanov T Vorherr E Carafoli 《The Journal of biological chemistry》1992,267(6):4097-4101
A monoclonal antibody against the human erythrocyte Ca2+ pump (1E4) reacted with the enzyme in intact erythrocytes. Using trypsinized preparations of the pump the antibody only reacted with the N-terminal fragments of 33.5 and 35 kDa. The fragments span from the N terminus (35 kDa) or from residue 19 (33.5 kDa) to residue 314 of the hPMCA4 isoform of the pump. Exhaustive degradation with a number of agents produced smaller peptides which reacted with the antibody. Sequencing analysis on two chymotryptic fragments of 8.8 and 13.5 kDa identified the epitope in an approximately 80-residue domain beginning with Gly-81. Two peptides corresponding to the putative extramembrane portions of this region of the pump were synthesized. The antibody reacted with one of them, spanning residues Phe-121 to Gly-152 and containing the first putative external loop of the pump. Peptides corresponding to overlapping portions of this peptide were synthesized, leading to the location of the epitope in a 13-residue sequence (Glu-130 to Glu-142) in the first predicted extracellular loop (Verma, A. K., Filoteo, A. G., Stanford, D. R., Wieben, E. D., Strehler, E. E., Fischer, R., Heim, R., Vogel, G., Mathews, S., Strehler-Page, M-A., James, P., Vorherr, T., Krebs, J., Penniston, J. T., and Carafoli, E. (1988) J. Biol. Chem. 263, 14152-14159). 相似文献
10.
Pestov NB Korneenko TV Shakhparonov MI Shull GE Modyanov NN 《American journal of physiology. Cell physiology》2006,291(2):C366-C374
The physiological functions of nongastric (colonic) H-K-ATPase (gene symbol Atp12a), unlike those of Na-K-ATPase and gastric H-K-ATPase, are poorly understood. It has been suggested that it pumps Na+ more efficiently than H+; however, so far, there is no direct evidence that it pumps H+ in vivo. Previously, we found that the nongastric H-K-ATPase -subunit is expressed in apical membranes of rodent anterior prostate epithelium, in a complex with the Na-K-ATPase 1-subunit. Here we report the effects of Atp12a gene ablation on polarization of the 1-subunit and secretory function of the anterior prostate. In nongastric H-K-ATPase-deficient prostate, the Na-K-ATPase -subunit resided exclusively in basolateral membranes; however, the 1-subunit disappeared from apical membranes, demonstrating that 1 is an authentic subunit of nongastric H-K-ATPase in vivo and that apical localization of 1 in the prostate is completely dependent on its association with the nongastric H-K-ATPase -subunit. A remarkable reduction in acidification of anterior prostate fluids was observed: pH 6.38 ± 0.14 for wild-type mice and 6.96 ± 0.10 for homozygous mutants. These results show that nongastric H-K-ATPase is required for acidification of luminal prostate fluids, thereby providing a strong in vivo correlate of previous functional expression studies demonstrating that it operates as a proton pump. hydrogen-potassium-adenosinetriphosphatase; male accessory glands; proton transport; sorting 相似文献