6-Azido-L-lysine HCl
Unnatural azido-modified amino acids for monitoring protein synthesis
| Size | Catalog No. | Price |
|---|---|---|
| 100 mg | BCAA-009-100 | € 140,00 |
Chemical Properties
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Molecular Formula
C6H12N4O2 *HCI
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Shelf Life
12 months unopened after receipt
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Storage Conditions
2-8 °C, dry
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Molecular Weight
172.19 g/mol * 36.45 g/mol
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Purity
≥ 98% (HPLC)
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Physical State
white crystalline powder
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CAS Number
1454334-76-9 (hydrochloride salt)
159610-92-1 (free acid) -
Additional name
H-L-Lys(N3)-OH*HCl; N-epsilon-Azido-L-lysine; (S)-2-Amino-6-azidohexanoic acid hydrochloride
Product Information
Bioorthogonal Protein Labeling with Lysine-Based Azide Chemistry
6-Azido-L-lysine hydrochloride ((S)-2-Amino-6-azidohexanoic acid hydrochloride) is a synthetic unnatural modified amino acid based derived from lysine, featuring an azide group at C6 instead of the natural amine. This modification enables site-specific protein labeling and bioorthogonal functionalization via Click Chemistry (SPAAC or CuAAC) or Staudinger ligation under mild conditions.
Incorporation Methods
- Genetic Code Expansion: Engineered tRNAs (based on prokaryotic tRNAs) recognize amber codons (usually UAG) and incorporate 6-Azido-L-lysine at a defined position during biosynthesis.
- Solid Phase Peptide Synthesis (SPPS): Allows chemical incorporation at any position in the peptide sequence for versatile functionalization.
After incorporation, the azide moiety reacts selectively with alkyne-modified partners (DBCO, BCN, PEGs, dyes) or P(III)-containing reagents, enabling efficient conjugation without side reactions.
Why choose 6-Azido-L-lysine?
Traditional NHS ester reacts with primary amines (e.g., lysines), leading to:
- Non-specific labeling at multiple sites
- Requires basic pH (8–9) and overnight reactions
- Risks for protein degradation and structural changes
In contrast, azide-based labeling with 6-Azido-L-lysine offers:
- Site-specific modification at the planned position
- Fast reactions at neutral pH with high yields
- Preserves tertiary structure
- Fully bioorthogonal, no interference with native functional groups
- Lower reagent consumption and atom-economic click chemistry for cost-effective, eco-friendly workflows
Applications of 6-Azido-L-lysine HCl
6-Azido-L-lysine is widely used for protein and peptide labeling, enabling precise site-specific modification through bioorthogonal click chemistry. It is an excellent choice for antibody modification and ADC synthesis, supporting the development of targeted therapeutics. This reagent also enables linking targeting moieties to proteins in drug delivery and diagnostic applications. Additionally, its compatibility as a building block for solid-phase peptide synthesis (SPPS) makes it ideal for custom peptide design in pharmaceutical development, biotechnology, and advanced biochemistry workflows.
Key Benefits
The main advantages of 6-Azido-L-lysine are:
- Integrity of tertiary structure: SPAAC and CuAAC reactions can be performed at neutral pH and in short reaction times. Therefore, the chemical modification of your peptide/protein is possible without the risk of the target biomolecule degrading.
- Fast & Efficient Click Reactions: The used click chemistry forms highly stable triazole bonds with all alkynes or alkyne derivates which can be used for strain-promoted alkyne-azide cycloaddition in a short reaction time.
- Specific labeling: Since 6-Azido-L-lysine is incorporated into your peptide/protein at a precisely defined position, highly specific labeling at this position is possible.
LITERATURE
Mapping the Ligand-Binding Site on a G Protein-Coupled Receptor (GPCR) Using Genetically Encoded Photocrosslinkers, Grunbeck et al., 2011, Biochemistry, Vol. 50, p. 3411-3413.
https://doi.org/10.1021/bi200214r
Proteomic Profiling of Burkholderia thailandensis During Host Infection Using Bio-Orthogonal Noncanonical Amino Acid Tagging (BONCAT), M. Franco et al., 2018, Frontiers in Cellular and Infection Microbiology, Vol. 8, 370.
https://doi.org/10.3389/fcimb.2018.00370
Discovery of cell active macrocyclic peptides with on-target inhibition of KRAS signaling, S. Lim et al., 2021, Chemical Science, Vol. 12(48), p. 15975-15987.
https://doi.org/10.1039/D1SC05187C
Peptidomimetic antibiotics disrupt the lipopolysaccharide transport bridge of drug-resistant Enterobacteriaceae, M. Schuster et al., 2023, Science Advances, Vol. 9(21), 3683.
https://doi.org/10.1126/sciadv.adg3683
Incorporating unnatural amino acids into recombinant proteins in living cells, Mitra, N., 2013, Materials and Methods, 3(204), 1.
https://doi.org/10.13070/mm.en.3.204
FAQ
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Is it possible to generate azide- or alkyne-modified peptides?
With modified amino acids azide- or alkyne-modified peptides can be prepared by solid-phase synthesis.
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How can de novo protein biosynthesis be monitored?
De novo protein biosynthesis can be monitored by feeding of metabolite analogues (so-called metabolic labeling) and subsequent click reaction. Azido-homoalanine for example is recognized as a methionine analogue and is incorporated into de novo synthesized proteins in methionine-free medium conditions. The resulting proteins contain azide moieties and thus can be detected after click to an alkyne-containing reporter molecule (e.g. a fluorescent dye). This non-radioactive method has major practical advantages compared to traditional 35S amino acid incorporation methods.
Alternatively, O-propargyl-puromycin is efficiently incorporated into proteins during de novo protein biosynthesis and can be used in complete medium. The resulting alkyne protein fragments can be detected via click to azide-containing reporter molecules. -
What click conditions should be used for protein click reactions?
A catalyst system based on CuSO4 and sodium ascorbate is recommended in combination with dye azides to label alkyne-modified proteins. Please also refer to our general Click protocols for more details.
Due to the 20 (21) amino acids that are the building blocks of proteins, the physicochemical properties of proteins are more diverse compared to oligonucleotides, which are just composed of 5 major building blocks. Therefore, finding the optimal click conditions is more difficult compared to oligonucleotides and labeling rates are usually lower. Please note that despite these difficulties detection applications (e.g. de novo protein biosynthesis detection) are easily feasible. -
Why use 6-Azido-L-lysine instead of NHS ester chemistry?
It provides a precise, site-specific labeling under mild conditions, avoiding multiple modification sites and preserving protein integrity.
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Which click reactions are supported?
SPAAC (copper-free) and CuAAC (copper-catalyzed) for rapid, efficient conjugation.
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Can it be used in SPPS?
Yes, it can be incorporated at any position during peptide synthesis.
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What labeling partners are compatible?
DBCO/BCN/primary alkyne-modified PEGs, fluorescent dyes, antibodies, and targeting moieties.