Half sphere exposure Half sphere exposure Half Sphere Exposure (HSE) is a protein solvent exposure measure that was first introduced by . Like all solvent exposure measures it measures how buried amino acid residues are in a protein. It is found by counting the number of amino acid neighbors within two half spheres of chosen radius around the amino acid. The calculation of HSE is found by dividing a contact number (CN) sphere in two halves by the plane perpendicular to the Cβ-Cα vector. This simple division of the CN sphere results in two strikingly different measures, HSE-up and HSE-down. HSE-up is defined
What Is This Thing Called Love? (Alexander O'Neal song) the United States, the single reached #21 on Billboard's Hot R&B/Hip-Hop Singles & Tracks. Credits are adapted from the album's liner notes. What Is This Thing Called Love? (Alexander O'Neal song) "What Is This Thing Called Love?" is a song written by Jimmy Jam and Terry Lewis and recorded by American recording artist Alexander O'Neal. It is the second single from the singer's fourth solo album, "All True Man" (1991). The song's distinctive backing vocals were performed by Lisa Keith. Following the successful chart performances of the "All True Man" single "All True Man", "What Is This Thing Called Love?"