کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1943789 1052685 2006 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Myoglobin with modified tetrapyrrole chromophores: Binding specificity and photochemistry
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش گیاه شناسی
پیش نمایش صفحه اول مقاله
Myoglobin with modified tetrapyrrole chromophores: Binding specificity and photochemistry
چکیده انگلیسی

Complexes were prepared of horse heart myoglobin with derivatives of (bacterio)chlorophylls and the linear tetrapyrrole, phycocyanobilin. Structural factors important for binding are (i) the presence of a central metal with open ligation site, which even induces binding of phycocyanobilin, and (ii) the absence of the hydrophobic esterifying alcohol, phytol. Binding is further modulated by the stereochemistry at the isocyclic ring. The binding pocket can act as a reaction chamber: with enolizable substrates, apo-myoglobin acts as a 132-epimerase converting, e.g., Zn-pheophorbide a' (132S) to a (132R). Light-induced reduction and oxidation of the bound pigments are accelerated as compared to solution. Some flexibility of the myoglobin is required for these reactions to occur; a nucleophile is required near the chromophores for photoreduction (Krasnovskii reaction), and oxygen for photooxidation. Oxidation of the bacteriochlorin in the complex and in aqueous solution continues in the dark.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1757, Issue 7, July 2006, Pages 750–763
نویسندگان
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