A Structural Biology Approach to Understand Human Lymphatic Filarial Infection
Figure 7
Chemical shift perturbations upon addition of human aspartic proteases.
(A) NMR Chemical shift Perturbations in Bm-Aspin due to different protease interactions at their saturated conditions. Chemical shift perturbations of the residues Y215 (i), I214 (ii), and A213 (iii) respectively, upon the addition of human aspartic proteases at their saturation levels. Free Bm-Aspin (Magenta), Bm-Aspin+Cathepsin-D (Yellow), Bm-Aspin+Cathepsin-E (Green), Bm-Aspin+Renin (Red), Bm-Aspin+Pepsin (Grey). (B) Comparison of Bm-Aspin chemical shift perturbation upon addition of human aspartic proteases. The bar diagram indicating the radial shift (calculated for each of the affected residues, by combining both the chemical shifts of 1H and 15N, using the equation: Radial shift displacement (Δδ) = {(Hf−Hb) 2+[(Nf−Nb)/6] 2} 1/2. A scaling factor of 6 was used to normalize the differences in the 1H and 15N spectral widths. Hf, Hb, Nf, and Nb are the chemical shifts of each residue's amide 1H and 15N in the free (Bm-Aspin alone) and bound (Bm-Aspin+protease complex) states, respectively) in ppm, observed due to NMR chemical shift perturbations in Bm-Aspin with the addition of proteases, (Bm-Aspin+Pepsin in blue, Bm-Aspin+Renin in red, Bm-Aspin+Cathepsin-E in green, Bm-Aspin+Cathepsin-D in magenta), observed for the following 10 residues: G16, G22, G82, G169, G190, A192, A204, A213, I214, and Y215.