peptideket

PeptideKet is a term encountered in peptide chemistry to describe peptides that bear a ketone functional group, enabling chemoselective ligation and labeling. The term is not universally standardized, and definitions vary across sources; in general it refers to peptides in which a ketone moiety is present either at the N-terminus as an amino ketone, at a side chain via a ketone-containing amino acid surrogate, or at the C-terminus through post-synthetic modification. PeptideKet constructs are typically prepared by incorporating a ketone-bearing amino acid analogue during solid-phase synthesis or by chemical modification after peptide assembly.

The ketone functionality in such peptides provides a reactive handle for bioconjugation. The most common reactions are oxime and hydrazone ligations with aminooxy or hydrazine derivatives, and various carbonyl-amine or carbonyl-nucleophile couplings under mildly basic or neutral conditions. These strategies enable attachment of fluorescent probes, affinity tags, or drug conjugates while preserving many peptide properties.

Practical considerations include the stability of the ketone under synthesis and storage conditions, the potential for side reactions with reducing agents, and the choice of protecting groups. The chemistry is generally compatible with aqueous buffers and standard peptide purification methods, though optimization is often required for each sequence.

See also: oxime ligation, hydrazone ligation, aminooxy compounds, peptide labeling. Note: 'PeptideKet' is a descriptive term rather than a fixed, universally adopted class.