Fmoc-Lys(Me)3-OH chloride (CAS 201004-29-7) is supplied as an Fmoc-protected trimethyllysine building block. In research synthesis, it is most relevant to site-defined trimethyllysine and histone/PTM peptide synthesis and histone-mimic peptides, PTM standards and methyl-lysine recognition studies.

Use it when the final sequence requires a permanent trimethylated lysine side chain; the chloride counterion belongs to the supplied salt form. Before substitution into an established synthesis, compare stereochemistry, protecting-group orthogonality and downstream deprotection requirements.

Product Information

Trimethyllysine as a Defined PTM

Fmoc-Lys(Me)3-OH chloride provides lysine with a permanently trimethylated side-chain ammonium group while retaining an Fmoc-protected alpha amino group for peptide assembly. This supports chemically defined methyl-lysine states rather than relying on enzymatic modification after synthesis.

Histone and Recognition Studies

Site-defined trimethyllysine peptides are used in histone-tail, antibody, reader-domain and analytical studies where methylation state must be controlled. Mono-, di- and trimethyllysine are different molecular entities and should not be treated as interchangeable PTM standards.

Salt Form and Mass Accounting

The chloride counterion is part of the supplied product form. Procurement records and molecular-weight calculations should distinguish the salt molecular weight from the residue mass represented after incorporation into the final peptide.

Additional chemistry is available in the specialty amino acid set. For synthesis planning beyond the building block, see specialty SPPS building blocks.

Product Documents

MSDS - Fmoc-Lys(Me)3-OH chloride (AS4244)

The Safety Data Sheet provides product identification, hazard information, handling and storage guidance, exposure controls, transport information, and regulatory information for laboratory use.

Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.

Frequently Asked Questions

What modification does Fmoc-Lys(Me)3-OH chloride encode?

It supplies lysine with a trimethylated side-chain ammonium group for site-defined incorporation during peptide synthesis.

Is this the same as backbone N-methyllysine?

No. The methyl groups are on the lysine side-chain nitrogen; the alpha amino group is Fmoc-protected for assembly.

Why is the chloride listed in the product name?

The trimethyllysine side chain is cationic, and chloride is the counterion in the supplied salt form.

Research Use Only.