Characterization of spindle checkpoint kinase Mps1 reveals domain with functional and structural similarities to tetratricopeptide repeat motifs of Bub1 and BubR1 checkpoint kinases - PubMed (original) (raw)

Biophysical characterization of the N-terminal fragment Mps1(1–239). Interfacial properties of Mps1(1–239), TPR Bub1, and TPR BubR1 are shown. Surface pressure (A) and surface concentration (Γ = 0.2 Δ) (B) together with the corresponding ellipsometric angle at air/water interfaces were determined by null ellipsometry measurements. Solutions of Mps1(1–239) (□), TPR Bub1 (○), and TPR BubR1 (●) are shown. Protein solutions were prepared at 30 μg/ml in 20 m

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phosphate buffer, pH 7. C, surface pressure versus surface concentration of Mps1(1–239) (□), TPR Bub1 (○), and TPR BubR1 (●). θ corresponds to the slope dπ/dΓ, and Γ0 is the surface concentration at which the surface pressure becomes different from zero. Γ0 is calculated from the intersect of the slope π versus Γ. Mps1(1–239) (□), TPR Bub1 (○), and TPR BubR1 (●) at 1 μg/ml in 20 m

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phosphate buffer, pH 7, are shown. D, rheology measurements of Mps1(1–239) (□), TPR Bub1 (○), and TPR BubR1 (●). The graph shows the evolution of the shear elastic constant, μ, versus time measured at the fixed frequency of 5 Hz, during protein adsorption at the interface. Protein solutions were prepared at 30 μg/ml in 20 m

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phosphate buffer, pH 7. The error bar on μ is ± 5 mN/m. Inset, at the end of the kinetic (around 9 h, indicated by the arrow in the graph) the angular deviation θ(ω) versus the pulsation was measured. The curves correspond to Mps1(1–239). An elastic layer model (harmonic oscillator) fit the imaginary and real part of the response. For clarity, the imaginary part has been plotted versus −ω.