Ac-Lys-OH contains an N-acetyl-protected lysine residue with a free carboxylic acid, corresponding to an amino acid derivative of the basic, aliphatic side-chain class. The molecule features a primary side-chain amine on the lysine backbone and an N-acetyl (Ac) group that modifies the α-amino functionality, yielding a protected α-amino acid while retaining the side-chain as a nucleophilic functional group. Ac-Lys-OH is used as a building block in peptide and amide synthesis and as a substrate or reference material in analytical and chemical biology workflows that require a lysine unit with controlled α-amino reactivity.
CAT No: CP26593
CAS No:1946-82-3
Synonyms/Alias:Ac-Lys-OH;N(alpha)-Acetyllysine;Nalpha-Acetyl-L-lysine;N2-Acetyl-L-lysine;(S)-2-Acetamido-6-aminohexanoicacid;N(alpha)-acetyl-L-lysine;N-alpha-Acetyl-L-lysine;N(2)-acetyl-L-lysine;N-ACETYL-L-LYSINE;(2S)-2-(acetylamino)-6-aminohexanoicacid;CHEBI:35704;L-Lysine,N2-acetyl-;VEYYWZRYIYDQJM-ZETCQYMHSA-N;SBB067149;(2S)-2-acetamido-6-aminohexanoicacid;(2S)-2-acetamido-6-amino-hexanoicacid;6-Amino-L-2-acetamidohexanoicacid;N.alpha.-Acetyllysine;.alpha.-Acetyl-L-lysine;N.alpha.-Acetyl-L-lysine;N|A-Acetyllysine;N|A-Acetyl-L-lysine;N-|A-Acetyl-L-lysine;bmse000830;N-alpha-Acetyl-L-lysine;N-ACETYL-L-LYSINE;Nalpha-Acetyl-L-lysine;N2-Acetyl-L-lysine;acetyl-l-lysine;N(alpha)-Acetyllysine;n-acetyllysine;(2S)-2-acetamido-6-aminohexanoic acid;N|A-Acetyl-L-lysine;L-Lysine, N2-acetyl-;N(alpha)-acetyl-L-lysine;N(2)-acetyl-L-lysine;(2S)-2-(acetylamino)-6-aminohexanoic acid;CHEBI:35704;6-Amino-L-2-acetamidohexanoic acid;Na-Acetyl-L-Lysine;7D44E6BN1B;N2-acetyllysine;MFCD00008233;(S)-2-Acetamido-6-aminohexanoic acid;N?-Acetyl-L-lysine;N.alpha.-Acetyllysine;.alpha.-Acetyl-L-lysine;N.alpha.-Acetyl-L-lysine;Lysine, N2-acetyl-, L-;UNII-7D44E6BN1B;acetyl-lysine;N-a-Acetyllysine;NSC-353625;6-Amino-L-2-acetamidohexanoic Acid;N2-Acetyl-L-lysine;N2-Acetyl-Lysine;N-Acetyl-L-lysine;Na-Acetyllysine;EINECS 217-747-5;N-a-Acetyl-L-lysine;N?-ACETYLLYSINE;lysine, alpha-N-acetyl-;bmse000830;Epitope ID:143648;SCHEMBL20529;N(.alpha.)-Acetyl-l-lysine;6-amino-l-2-acetamidohexanoate;CHEMBL1241437;DTXSID501036027;s3345;AKOS015837751;HY-W048838;NSC 353625;(2S)-6-amino-2-acetamidohexanoic acid;AS-46851;N-alpha-Acetyl-L-lysine (Ac-L-Lys-OH);A2171;CS-0101238;NS00046545;F10720;EN300-1699962;Q27104319;Z1255438452
Ac-Lys-OH is an N-acetylated lysine derivative supplied as a free amino acid building block for peptide chemistry and intermediate preparation. The molecule retains the lysine side-chain primary amine while the α-amino group is capped with an acetyl group, which influences reactivity and downstream coupling behavior. This structure is commonly used in workflows where control of amine chemoselectivity and defined lysine functionality are required for segment assembly, derivatization, and analytical reference material preparation.
1. Lysine Building Block Use
Ac-Lys-OH is used as a lysine-containing amino acid building block in peptide and peptidomimetic synthesis where the α-amino group is already protected as an acetamide. Researchers developing short peptides, peptide fragments, or lysine-rich sequences often select this form to manage coupling selectivity and to maintain the side-chain ε-amine as the primary reactive handle for subsequent functionalization. In custom peptide manufacturing and medicinal chemistry support, Ac-Lys-OH helps standardize lysine incorporation when a defined N-acetyl terminus is desired for stability studies, SAR analog generation, or to match reference material structures used in method development.
2. Side-Chain Functionalization Intermediate
Ac-Lys-OH serves as a practical intermediate for derivatization reactions that target the lysine ε-amine while keeping the α-amino group masked as an acetamide. Chemical biology and bioconjugation teams frequently use this reagent to prepare lysine-based intermediates for downstream attachment to polymers, linkers, or biomolecule scaffolds, leveraging the preserved primary amine for selective coupling chemistry. Pharmaceutical intermediate development groups also rely on Ac-Lys-OH to build defined lysine derivatives used in library synthesis and in the preparation of standardized reagents for assay development and characterization workflows.
3. Reference Standard Preparation
Ac-Lys-OH is employed as a structural reference and analytical standard component in LC-MS and related characterization workflows where an N-acetylated lysine species is required. Analytical chemists and peptide quality-control laboratories use lysine derivatives like this to verify retention behavior, fragmentation patterns, and method performance for peptide-related samples, including monitoring of lysine-containing intermediates and reaction mixtures. Because the acetylated α-amino functionality is part of the defined analyte identity, Ac-Lys-OH is particularly useful when distinguishing N-acetylated lysine from free lysine or other differently protected lysine analogs during analytical method development and troubleshooting.
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