排序方式: 共有6条查询结果,搜索用时 0 毫秒
1
1.
Calligari PA Salgado GF Pelupessy P Lopes P Ouazzani J Bodenhausen G Abergel D 《Proteins》2012,80(4):1196-1210
Nuclear magnetic resonance is used to investigate the backbone dynamics in 6-phosphogluconolactonase from Trypanosoma brucei (Tb6PGL) with (holo-) and without (apo-) 6-phosphogluconic acid as ligand. Relaxation data were analyzed using the model-free approach and reduced spectral density mapping. Comparison of predictions, based on 77 ns molecular dynamics simulations, with the observed relaxation rates gives insight into dynamical properties of the protein and their alteration on ligand binding. Data indicate dynamics changes in the vicinity of the binding site. More interesting is the presence of perturbations located in remote regions of this well-structured globular protein in which no large-amplitude motions are involved. This suggests that delocalized changes in dynamics that occur upon binding could be a general feature of protein-target interactions. 相似文献
2.
The first gluconolactonase crystal structure from bacteria has been determined to a resolution of 1.61 Å using X-ray crystallography. It belongs to the senescence marker protein 30/gluconolaconase superfamily but exhibits substrate specificity mainly toward d-glucono-δ-lactone. It forms a novel disulfide-bonded clamshell dimer comprising two doughnut-shaped six-bladed β-propeller domains, yet with an exceptionally long N-terminal subdomain forming an extra helix and four additional β-strands to enclose half of the outermost β-strands of each propeller. Extensive interactions, including H-bonds, salt bridges, disulfide bonds, and coordination bonds, along with numerous bridging water molecules, are present in the interface to institute the “top-to-top” clamshell-type dimer. Three calcium ions per subunit were observed. Two are present in the central water-filled channel, with the top one coordinated to four highly conserved amino acids and is possibly involved in substrate hydrolysis, while the bottom one is coordinated to the backbone oxygen atoms, which is possibly for stabilizing the propeller domain. One calcium ion is situated in the interface also to stabilize the dimer form. Since gluconolactonase is essential in the glucose secondary metabolic pathways leading to the synthesis of pentose, vitamin C, or “antiaging” factors, determination of its tertiary structure should help understand these important biochemical processes. 相似文献
3.
Vitamin C depletion increases superoxide generation in brains of SMP30/GNL knockout mice 总被引:1,自引:0,他引:1
Kondo Y Sasaki T Sato Y Amano A Aizawa S Iwama M Handa S Shimada N Fukuda M Akita M Lee J Jeong KS Maruyama N Ishigami A 《Biochemical and biophysical research communications》2008,377(1):291-296
Vitamin C (VC) has a strong antioxidant function evident as its ability to scavenge superoxide radicals in vitro. We verified that this property actually exists in vivo by using a real-time imaging system in which Lucigenin is the chemiluminescent probe for detecting superoxide in senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize VC in vivo. SMP30/GNL KO mice were given 1.5 g/L VC [VC(+)] for 2, 4, or 8 weeks or denied VC [VC(−)]. At 4 and 8 weeks, VC levels in brains from VC(−) KO mice were <6% of that in VC(+) KO mice. Accordingly, superoxide-dependent chemiluminescence levels determined by ischemia-reperfusion at the 4- and 8 weeks test intervals were 3.0-fold and 2.1-fold higher, respectively, in VC(−) KO mice than in VC(+) KO mice. However, total superoxide dismutase activity and protein levels were not altered. Thus, VC depletion specifically increased superoxide generation in a model of the living brain. 相似文献
4.
Akinori Kashio Akiko Amano Takashi Sakamoto Mitsuya Suzuki Tatsuya Yamasoba 《Biochemical and biophysical research communications》2009,390(3):394-2294
Using senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize vitamin C (VC), we examined whether modulating VC level affects age-related hearing loss (AHL). KO and wild-type (WT) C57BL/6 mice were given water containing 1.5 g/L VC [VC(+)] or 37.5 mg/L VC [VC(−)]. At 10 months of age, KO VC(−) mice showed significant reduction in VC level in the inner ear, plasma, and liver, increase in auditory brainstem response (ABR) thresholds, and decrease in the number of spiral ganglion cells compared to WT VC(−), WT VC(+), and KO VC(+) mice. There were no differences in VC level in the inner ear, ABR thresholds, or the number of spiral ganglion cells among WT VC(−), WT VC(+), and KO VC(+) mice. These findings suggest that VC depletion can accelerate AHL but that supplementing VC may not increase VC level in the inner ear or slow AHL in mice. 相似文献
5.
Hydrogen-rich pure water prevents superoxide formation in brain slices of vitamin C-depleted SMP30/GNL knockout mice 总被引:1,自引:0,他引:1
Sato Y Kajiyama S Amano A Kondo Y Sasaki T Handa S Takahashi R Fukui M Hasegawa G Nakamura N Fujinawa H Mori T Ohta M Obayashi H Maruyama N Ishigami A 《Biochemical and biophysical research communications》2008,375(3):346-350
Hydrogen is an established anti-oxidant that prevents acute oxidative stress. To clarify the mechanism of hydrogen’s effect in the brain, we administered hydrogen-rich pure water (H2) to senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize vitamin C (VC), also a well-known anti-oxidant. These KO mice were divided into three groups; recipients of H2, VC, or pure water (H2O), administered for 33 days. VC levels in H2 and H2O groups were <6% of those in the VC group. Subsequently, superoxide formation during hypoxia-reoxygenation treatment of brain slices from these groups was estimated by a real-time biography imaging system, which models living brain tissues, with Lucigenin used as chemiluminescence probe for superoxide. A significant 27.2% less superoxide formed in the H2 group subjected to ischemia-reperfusion than in the H2O group. Thus hydrogen-rich pure water acts as an anti-oxidant in the brain slices and prevents superoxide formation. 相似文献
6.
1