tailieunhanh - Báo cáo khoa học: Does different orientation of the methoxy groups of ubiquinone-10 in the reaction centre of Rhodobacter sphaeroides cause different binding at QA and QB?

The different roles of ubiquinone-10 (UQ10) at the primary and secondary quinone (QAand QB) binding sites ofRho-dobacter sphaeroidesR26 reaction centres are governed by the protein microenvironment. The 4C¼O carbonyl group of QAis unusually strongly hydrogen-bonded, in contrast to QB. This asymmetric binding seems to determine their dif-ferent functions. The asymmetric hydrogen-bonding at QA can be caused intrinsically by distortion of the methoxy groups or extrinsically by binding to specific amino-acid side groups. . | Eur. J. Biochem. 270 3603-3609 2003 FEBS 2003 doi Does different orientation of the methoxy groups of ubiquinone-10 in the reaction centre of Rhodobacter sphaeroides cause different binding at QA and QB Andre Remy1 Rutger B. Boers2 Tatiana Egorova-Zachernyuk2 Peter Gast3 Johan Lugtenburg2 and Klaus Gerwert1 1Lehrstuhl fur Biophysik Ruhr-Universitdt Bochum Germany 2Department of Chemistry Gorlaeus Laboratories Leiden University the Netherlands 3Department of Biophysics Huygens Laboratory Leiden University the Netherlands The different roles of ubiquinone-10 UQ10 at the primary and secondary quinone QA and QB binding sites of Rho-dobacter sphaeroides R26 reaction centres are governed by the protein microenvironment. The 4C O carbonyl group of Qa is unusually strongly hydrogen-bonded in contrast to QB. This asymmetric binding seems to determine their different functions. The asymmetric hydrogen-bonding at QA can be caused intrinsically by distortion of the methoxy groups or extrinsically by binding to specific amino-acid side groups. Different X-ray-based structural models show contradictory orientations of the methoxy groups and do not provide a clear picture. To elucidate if distortion of the methoxy groups induces this hydrogen-bonding their ring- C-O vibrations were assigned by use of site-specifically labelled 5-13C UQ10 and 6-13C UQ10 reconstituted at either the QA or the QB binding site. Two infrared bands at 1288 cm-1 and 1264 cm-1 were assigned to the methoxy vibrations. They did not shift in frequency at either the QA or Qb binding sites as compared with unbound UQ10. As the frequencies of these vibrations and their coupling are sensitive to the conformations of the methoxy groups different conformations of the C 5 and C 6 methoxy groups at the Qa and Qb binding sites can now be excluded. Both methoxy groups are oriented out of plane at QA and QB. Therefore hydrogen-bonding to His M219 combined with electrostatic interactions

• Báo cáo khoa học
• scientific reports
• Report medicine
• traditional medicine
• breast cancer
• biological activities
• gastric cancer
• BMC Cancer
• Gastric cancer incidence
• Population based specialized registry
• Gastric cancer survival
• Gastric cancer clinical characteristics
• Gastric cancer pathological characteristics
• Gastroesophageal junction cancer
• Gastric cancer genomics
• Gastric cancer sequencing
• Gastric neoplasm
• D2 lymphadenectomy
• Advanced gastric cancer
• Gastric cancer surgery
• Cancer associated fibroblast
• Anti apoptosis
• Tumor cells
• Non cancerous gastric fibroblasts
• Transcription factors
• Cancer cell growth
• Potential therapeutic
• Emerging evidence
• Cancer development
• Transwell migration
• Matrigel invasion
• Cancer screening
• Discrete choice experiment
• Overall survival
• Gastric lymphoma
• Metachronous gastric adenocarcinoma
• Diffuse large B cell lymphoma
• Primary gastric lymphoma
• Diffuse gastric cancer
• Magnetic resonance imaging
• Heterogeneous enhancement
• BALB/c nude mice model
• Human originated gastric cancer cell
• Immune infiltration
• RNA seq data
• Stomach adenocarcinoma
• Tumor infiltrating immune cells
• Programmed cell death 1
• Tumor immunity
• Immune cells besides T cells
• Palliative chemotherapy
• Combination chemotherapy
• Germline mutation
• Central America
• CA 4
• Case report
• Early gastric cancer
• Splenic metastasis
• Epstein Barr virus
• Stomach cancer
• Gastric carcinoma
• Meta analysis
• Cetuximab combined
• Metastatic gastric cancer
• Identify potential biomarkers
• Target drugs
• Recurrent gastric cancer
• Traditional chemotherapy
• Mouse models
• Human gastric cancer
• Tumor formation
• Plasma membrane
• Tumor biomarkers
• Plasma membrane proteins participate
• Vascular endothelial growth factor
• 5 fluorouracil
• Single nucleotide polymorphisms
• HER2 positive recurrent
• Primary metastatic gastric cancer
• Trastuzumab based chemotherapy
• Severe postoperative complications
• Receiver operating characteristic
• Surgical gastric cancer
• Propensity score
• Adjuvant treatment
• Localized gastric cancer
• DNA sequencing
• CDH1 mutations
• Cell adhesion protein
• Mixed gastric cancer
• Metastasis associated lung adenocarcinoma transcript 1
• Cancer globally
• Non coding RNAs
• Including gastric cancer