Water in the Active Site of Ketosteroid Isomerase
نویسندگان
چکیده
منابع مشابه
Hydrogen bond coupling in the ketosteroid isomerase active site.
Hydrogen bond networks are key elements of biological structure and function. Nevertheless, their structural properties are challenging to assess within complex macromolecules. Hydrogen-bonded protons are not observed in the vast majority of protein X-ray structures, and static crystallographic models provide limited information regarding the dynamical coupling within hydrogen bond networks. We...
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Within the idiosyncratic enzyme active-site environment, side chain and ligand pKa values can be profoundly perturbed relative to their values in aqueous solution. Whereas structural inspection of systems has often attributed perturbed pKa values to dominant contributions from placement near charged groups or within hydrophobic pockets, Tyr57 of a Pseudomonas putida ketosteroid isomerase (KSI) ...
متن کاملProton affinity of the oxyanion hole in the active site of ketosteroid isomerase.
The absorption spectra of a series of inhibitors bound at the active site of Delta(5)-3-ketosteroid isomerase from Pseudomonas putida were found to exhibit substantial variations in the contributions of the protonated and deprotonated forms. Systematic variation of the inhibitor solution pK(a) combined with a method of quantifying the contributions of each protonation state showed the oxyanion ...
متن کاملSolvation response along the reaction coordinate in the active site of ketosteroid isomerase.
A light-activated reaction analog has been developed to mimic the catalytic reaction cycle of Delta(5)-3-ketosteroid isomerase to probe the functionally relevant protein solvation response to the catalytic charge transfer. Delta(5)-3-ketosteroid isomerase from Pseudomonas putida catalyzes a C-H bond cleavage and formation through an enolate intermediate. Conversion of the ketone substrate to th...
متن کاملQuantitative, directional measurement of electric field heterogeneity in the active site of ketosteroid isomerase.
Understanding the electrostatic forces and features within highly heterogeneous, anisotropic, and chemically complex enzyme active sites and their connection to biological catalysis remains a longstanding challenge, in part due to the paucity of incisive experimental probes of electrostatic properties within proteins. To quantitatively assess the landscape of electrostatic fields at discrete lo...
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ژورنال
عنوان ژورنال: Biochemistry
سال: 2011
ISSN: 0006-2960,1520-4995
DOI: 10.1021/bi200703y