کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5504271 | 1536271 | 2017 | 32 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Evolutionary conservation of EF-hand ÎÎ loop in aequorin: Priority of intensity to decay rate in bioluminescence emission
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
As a Ca2+-regulated photoprotein, aequorin (Aeq) contains four EF-hand motifs, the second one lacks the standard sequence for Ca2+ coordination and doesn't bind to Ca2+. Here, we replaced this loop with a functional loop. According to structural studies, although the global stability of modified aequorin (4EFAeq) is higher than that of Aeq; increasing the local flexibility accompanied by internal structural rearrangements in 4EFAeq result in its penetrability to urea and acrylamide. A fast decay rate was observed for 4EFAeq. Assuming the presence of intermediate states in the luminescent reaction, this observation indicate that the loop replacement leads to the lowering of the half-life of intermediate states which results in increasing the rate of conformational switching of 4EFAeq to light emitting form. However, considerable reduction in initial luminescence intensity of 4EFAeq suggests that the number of functional complexes is reduced. Our findings demonstrate that the conformational effects of the second loop in Aeq elicit a delicate balance between local flexibility and global stability which may be considered as an important functional parameter in photoproteins. It was also concluded that evolutionary conservation of EF-hand ÎÎ in the current form is a consequence of priority of intensity to decay rate in bioluminescent organisms.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 634, 15 November 2017, Pages 29-37
Journal: Archives of Biochemistry and Biophysics - Volume 634, 15 November 2017, Pages 29-37
نویسندگان
Mahsa Ebrahimi, Ammar Mohseni, Khosrow Khalifeh, Bijan Ranjbar, Reza H. Sajedi,