کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10795335 | 1052572 | 2015 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Physicochemical nature of interfaces controlling ferredoxin NADP+ reductase activity through its interprotein interactions with ferredoxin
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کلمات کلیدی
SIRferredoxin NADP+ reductaseFNRHSQCITCNADPHflavin adenine dinucleotidenuclear magnetic resonance - رزونانس مغناطیسی هستهایchemical shift perturbation - اختلال حرکت شیمیاییelectron transfer - انتقال الکترونGibbs free energy - انرژی آزاد گیبسFAD - بدBinding thermodynamics - ترمودینامیک اتصالNMR - تشدید مغناطیسی هستهای Electrostatic interaction - تعامل الکترواستاتیکHydrophobic interaction - تعامل هیدروفوبیکEntropy change - تغییر آنتروپیHeat capacity change - تغییر ظرفیت حرارتیenthalpy change - تغییرات آنتالپیcircular dichroism - رنگ تابی دورانیSulfite reductase - سولفید ردوکتازFerredoxin - فریدوکسیینEnzyme activity - فعالیت آنزیمnicotinamide adenine dinucleotide phosphate - نیکوتین آمید adenine dinucleotide phosphateHeteronuclear Single Quantum Correlation - همبستگی کوانتومی تک هسته ای تنهاIsothermal titration calorimetry - کالری سنجی تیتاسیون ایزوترمال
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Although acidic residues of ferredoxin (Fd) are known to be essential for activities of various Fd-dependent enzymes, including ferredoxin NADP+ reductase (FNR) and sulfite reductase (SiR), through electrostatic interactions with basic residues of partner enzymes, non-electrostatic contributions such as hydrophobic forces remain largely unknown. We herein demonstrated that intermolecular hydrophobic and charge-charge interactions between Fd and enzymes were both critical for enzymatic activity. Systematic site-directed mutagenesis, which altered physicochemical properties of residues on the interfaces of Fd for FNR /SiR, revealed various changes in activities of both enzymes. The replacement of serine 43 of Fd to a hydrophobic residue (S43W) and charged residue (S43D) increased and decreased FNR activity, respectively, while S43W showed significantly lower SiR activity without affecting SiR activity by S43D, suggesting that hydrophobic and electrostatic interprotein forces affected FNR activity. Enzyme kinetics revealed that changes in FNR activity by mutating Fd correlated with Km, but not with kcat or activation energy, indicating that interprotein interactions determined FNR activity. Calorimetry-based binding thermodynamics between Fd and FNR showed different binding modes of FNR to wild-type, S43W, or S43D, which were controlled by enthalpy and entropy, as shown by the driving force plot. Residue-based NMR spectroscopy of 15N FNR with Fds also revealed distinct binding modes of each complex based on different directions of NMR peak shifts with similar overall chemical shift differences. We proposed that subtle adjustments in both hydrophobic and electrostatic forces were critical for enzymatic activity, and these results may be applicable to protein-based electron transfer systems.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1847, Issue 10, October 2015, Pages 1200-1211
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1847, Issue 10, October 2015, Pages 1200-1211
نویسندگان
Misaki Kinoshita, Ju yaen Kim, Satoshi Kume, Yukiko Sakakibara, Toshihiko Sugiki, Chojiro Kojima, Genji Kurisu, Takahisa Ikegami, Toshiharu Hase, Yoko Kimata-Ariga, Young-Ho Lee,