کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1926940 1536491 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tuning of the FMN binding and oxido-reduction properties by neighboring side chains in Anabaena flavodoxin
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Tuning of the FMN binding and oxido-reduction properties by neighboring side chains in Anabaena flavodoxin
چکیده انگلیسی

Contribution of three regions (phosphate-binding, 50’s and 90’s loops) of Anabaena apoflavodoxin to FMN binding and reduction potential was studied. Thr12 and Glu16 did not influence FMN redox properties, but Thr12 played a role in FMN binding. Replacement of Trp57 with Glu, Lys or Arg moderately shifted Eox/sq and Esq/hq and altered the energetic of the FMN redox states binding profile. Our data indicate that the side chain of position 57 does not modulate Eox/sq by aromatic stacking or solvent exclusion, but rather by influencing the relative strength of the H-bond between the N(5) of the flavin and the Asn58-Ile59 bond. A correlation was observed between the isoalloxazine increase in solvent accessibility and less negative Esq/hq. Moreover, Esq/hq became less negative as positively charged residues were added near to the isoalloxazine. Ile59 and Ile92 were simultaneously mutated to Ala or Glu. These mutations impaired FMN binding, while shifting Esq/hq to less negative values and Eox/sq to more negative. These effects are discussed on the bases of the X-ray structures of some of the Fld mutants, suggesting that in Anabaena Fld the structural control of both electron transfer steps is much more subtle than in other Flds.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 467, Issue 2, 15 November 2007, Pages 206–217
نویسندگان
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