Carboxylterminala

Carboxylterminala is a term used to denote the carboxyl-terminal region of a protein or peptide, commonly referred to in English as the C-terminus. It represents the end of the polypeptide chain that bears a free carboxyl group, in contrast to the amino-terminal (N-terminal) end. In many contexts, carboxylterminala is synonymous with C-terminus, and its characterization helps describe sequence orientation and terminal modifications.

The C-terminus defines the final residue in the amino acid sequence and can influence protein stability, folding, and interactions. In natural proteins, the C-terminus may be unmodified or subject to post-translational changes such as amidation, truncation, or lipidation. Certain C-terminal motifs, such as CAAX or other sorting signals, can direct subcellular localization, trafficking, or membrane association.

Post-translational modifications at the carboxyl terminus include C-terminal amidation, which creates a stable amide group and is common in many peptide hormones and neuropeptides. Prenylation or other lipid attachments can also occur at specific C-terminal motifs, affecting membrane affinity and protein targeting. Proteolytic processing often trims the C-terminus, altering function or activity.

In research and annotation, the carboxylterminala is considered when describing protein topology, domain boundaries, and interaction interfaces. Techniques such as mass spectrometry and specialized sequencing approaches are used to characterize the exact C-terminal sequence and any terminal modifications, contributing to a fuller understanding of protein function and regulation.