Cterminukseen

Cterminukseen is the Finnish illative form used in scientific texts to describe movement toward the C-terminus of a protein or polypeptide. In English, the corresponding term is the C-terminus or carboxy terminus, referring to the end of a polypeptide chain that carries the free carboxyl group, opposite the N-terminus.

The C-terminus is defined by the amino acid sequence at the end of a protein. Its composition and context influence protein folding, stability, interactions, and localization within the cell. Many proteins contain C-terminal motifs that regulate binding to other proteins or membranes. The C-terminus can also undergo post-translational modifications, such as C-terminal amidation, prenylation at a CaaX motif, or attachment of a GPI anchor, which can affect localization and function.

Experimental and practical aspects include studying the C-terminus by truncating the protein, introducing point mutations, or appending purification or detection tags at the C-terminus. C-terminal tags (for example, His-tag, FLAG-tag, or fluorescent protein fusions) facilitate purification and visualization. Proteolytic processing during maturation can remove or alter the C-terminus, and certain C-terminal motifs mediate interactions with other proteins through domains like PDZ.

In sequence analysis and protein engineering, the C-terminus is treated as a defined terminus for annotations, comparative studies, and functional assays. The term Cterminukseen thus situates discussions of protein ends within Finnish-language scientific writing, while referring to the broader concept of the C-terminus in molecular biology.