The root mean square distance between an object and the centre of gravity is defined as the radius of gyration (Rg). The radius of gyration is a measure of the compactness of the protein structure, where higher Rg value is referred to as a less compact structure, and low Rg value is inferred as high compactness that implies more stability. The measured average Rg values of RBD Spro, RBD Spro-Piperine, Mpro and Mpro-Piperine are 1.829 ± 0.008 nm, 1.833 ± 0.010 nm, 2.233 ± 0.012 nm and 2.238 ± 0.013 nm, respectively. From Figure 7(a,b), it is observed that there is a little enhancement in the Rg values of RBD Spro-Piperin, and Mpro-Piperine as compared to RBD Spro and Mpro, which implies to the gain in compactness of the protein structures upon binding to Piperine.