Calpha

Calpha is a term used in multiple domains and does not have a single, universal meaning. Its interpretation depends on the field and the context in which it appears.

In biochemistry and structural biology, Cα (often written Cα or C-alpha) denotes the alpha carbon of an amino acid. This is the central carbon atom to which the amino group, carboxyl group, hydrogen, and the side chain are attached. The Cα atom serves as a reference point for the protein backbone and is central to describing residue geometry, dihedral angles (phi and psi), and the overall fold. Structural data sets and modeling approaches frequently use Cα coordinates to construct simplified representations of proteins, such as Cα traces.

In other contexts, Calpha may appear as informal shorthand, a transliteration, or a proper noun in project names, products, or brands. It is not a standard chemical element symbol or universal constant. When encountered, the intended meaning is typically clarified by the surrounding text or accompanying definitions. Readers should rely on domain-specific cues to interpret it correctly.