Backbone dynamics of the cytotoxic Ribonuclease &agr;-sarcin by 15N NMR relaxation methods

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• 作者：Pé ; rez Cañ ; adillas ; José ; Manuel ; Guenneugues ; Marc ; Campos Olivas ; Ramó ; n ; Santoro ; Jorge ; Mart&iacute ; nez del Pozo ; Alvaro ; Gavilanes ; José ; G. ; Rico ; Manuel ; Bruix ; Marta
• 关键词：sarcin ; model ; free analysis ; NMR relaxation ; protein dynamics ; reduced spectral density mapping
• 刊名：Journal of Biomolecular NMR
• 出版年：2002
• 出版时间：2002
• 年：2002
• 卷：24
• 期：4
• 页码：301-316
• 全文大小：554 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Biophysics and Biomedical Physics
  Polymer Sciences
  Biochemistry
  
• 出版者：Springer Netherlands
• ISSN：1573-5001

文摘

The cytotoxic ribonuclease &agr;-sarcin is a 150-residue protein that inactivates ribosomes by selectively cleaving a single phosphodiester bond in a strictly conserved rRNA loop. In order to gain insights on the molecular basis of its highly specific activity, we have previously determined its solution structure and studied its electrostatics properties. Here, we complement those studies by analysing the backbone dynamics of &agr;-sarcin through measurement of longitudinal relaxation rates R₁, off resonance rotating frame relaxation rates R₁&rgr;, and the ¹⁵N¹HNOE of the backbone amide ¹⁵N nuclei at two different magnetic field strengths (11.7 and 17.6 T). The two sets of relaxation parameters have been analysed in terms of the reduced spectral density mapping formalism, as well as by the model-free approach. &agr;-Sarcin behaves as an axial symmetric rotor of the prolate type (D_∥/D_⊥