Half sphere exposure used in predicting discontinuous B-cell epitopes. Song et al. have developed an online webserver termed HSEpred to predict half-sphere exposure from protein primary sequences. HSEpred server can achieve the correlation coefficients of 0.72 and 0.68 between the predicted and observed HSE-up and HSE-down measures, respectively, when evaluated on a well-prepared non-homologous protein structure dataset. Moreover, residue contact number (CN) can also be accurately predicted by HSEpred webserver using the summation of the predicted HSE-up and HSE-down values, which has further enlarged the application of this new solvent exposure measure. Recently, Heffernan et al. has developed the most accurate predictor for
N-sphere a central point, where the radius may be any positive real number. Thus, the -sphere would be defined by: In particular: An "n"-sphere embedded in an -dimensional Euclidean space is called a hypersphere. The -sphere of unit radius is called the unit -sphere, denoted , often referred to as "the" -sphere. When embedded as described, an -sphere is the surface or boundary of an -dimensional ball. For , the -spheres are the simply connected -dimensional manifolds of constant, positive curvature. The -spheres admit several other topological descriptions: for example, they can be constructed by gluing two -dimensional Euclidean spaces together,