کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5394884 | 1505650 | 2011 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Increasing complexity models for describing the generation of substrate radicals at the active site of ethanolamine ammonia-lyase/B12
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Increasing complexity models for describing the generation of substrate radicals at the active site of ethanolamine ammonia-lyase/B12 Increasing complexity models for describing the generation of substrate radicals at the active site of ethanolamine ammonia-lyase/B12](/preview/png/5394884.png)
چکیده انگلیسی
Here we assess at the PCM//UB3LYP/6-31G(d,p) level how using a complete molecular description of both reactants in step b and introducing the polarizing effect of the protein/cofactor environment (mimicked through a continuum model with ε = 10) impacts on the nature and energetics of the intermediate complexes (ICs) and transition states (TSs) under three catalytic scenarios (total, partial, and no protonation). Our results show that a concerted asynchronous mechanism involving distonic radical species is at play, passing through quasi-linear early TSs displaying a C1-H cleavage slightly more advanced than formation of the new H-C bond in Ado. Whereas the enzyme's polarizing environment differentially stabilizes the TS lowering the barrier by â¼2.4-2.8 kcal/mol, a reduction of 1.4 kcal/mol in ÎG298â is the outcome of substrate's partial/total protonation, without a clear distinction among them, in opposition to what previously shown based upon more simplified models.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computational and Theoretical Chemistry - Volume 975, Issues 1â3, 15 November 2011, Pages 52-60
Journal: Computational and Theoretical Chemistry - Volume 975, Issues 1â3, 15 November 2011, Pages 52-60
نویسندگان
Jenner N. Bonanata, Santiago Signorelli, E. Laura Coitiño,