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
Sphere spectrum Sphere spectrum In stable homotopy theory, a branch of mathematics, the sphere spectrum "S" is the initial object in the category of spectra. It is the suspension spectrum of "S", i.e., a set of two points. Explicitly, the "n"th space in the sphere spectrum is the "n"-dimensional sphere "S", and the structure maps from the suspension of "S" to "S" are the canonical homeomorphisms. The "k"-th homotopy group of a sphere spectrum is the "k"-th stable homotopy group of spheres. The localization of the sphere spectrum at a prime number "p" is called the local sphere at "p" and is