کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6493163 | 1418046 | 2018 | 30 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular mechanisms governing the evolutionary conservation of Glycine in the 6th position of loops ÎÎÎ and ÎV in photoprotein mnemiopsin 2
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Molecular mechanisms governing the evolutionary conservation of Glycine in the 6th position of loops ÎÎÎ and ÎV in photoprotein mnemiopsin 2 Molecular mechanisms governing the evolutionary conservation of Glycine in the 6th position of loops ÎÎÎ and ÎV in photoprotein mnemiopsin 2](/preview/png/6493163.png)
چکیده انگلیسی
Photoproteins in their functional form are complexed noncovalently with 2-hydroperoxycoelenterazine. A conformational change upon coordination of Ca+2 ions with their EF-hand loops leads to oxidation of substrate and emission of light. In all photoproteins, EF-hand loops Î, ÎÎÎ and ÎV have standard sequence for binding to Ca+2 ion, however the second one is not able for Ca+2 coordination. Sequence analysis of Mnemiopsin 2 and other known photoproteins shows that Glutamate (Glu) is occurred in the 6th position of its first EF-hand loop, but this position in other loops of mnemiopsin 2 and all functional loops of other photoproteins is occupied by Glycine (Gly). Here we designed and made single and double mutants where Gly residue at the 6th positions of loops ÎÎÎ and ÎV of mnemiopsin 2 was replaced with Glu. According to the activity measurements, wild-type (WT) and G142E variants have more initial luminescence intensity than G176E and double mutants; while WT and G176E have higher values of half decay time when compared with G142E and double mutants. According to the isothermal denaturation experiments, all protein variants are structurally more stable than WT mnemiopsin 2 and that the stabilizing effects of single mutants are paired resulting in more stability of double mutant against urea denaturation. We concluded that simultaneous occurrence of Gly in the 6th position of loops ÎÎÎ and ÎV is essential for evolutionary adjustment of initial intensity and decay rate of luminescence emission via affecting the interaction of the core structure of photoprotein with coelenteramide and binding affinity of Ca+2 to the corresponding loops, respectively.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 187, October 2018, Pages 18-24
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 187, October 2018, Pages 18-24
نویسندگان
Roghayeh Mohammadi Ghanbarlou, Seyedeh Akram Shirdel, Vahab Jafarian, Khosrow Khalifeh,