CHEMOSELECTIVE CONJUGATION
Copper-free click chemistry
Azide–DBCO or azide–BCN coupling is a useful option for site-defined peptide–PNA assembly without adding a copper catalyst.
Azide–PNA
+
DBCO–Peptide
→
Peptide–PNA
Attachment handles
Azide and strained alkyne (DBCO or BCN), placed on complementary components.
Key advantage
Site-defined coupling with a generally straightforward byproduct profile.
Design check
Handle placement, steric accessibility, reagent stability, and purification of excess starting material.
Research fit
Defined CPP–PNA, targeting peptide–PNA, and other custom architectures.
REACTIVE HANDLE COUPLING
Thiol–maleimide chemistry
Terminal or appropriately positioned thiols can react with maleimide-functionalized partners for efficient peptide–PNA coupling.
Thiol–Peptide
+
Maleimide–PNA
→
Conjugate
Attachment handles
Free thiol and maleimide; thiol availability and protection must be planned.
Key advantage
Practical route for feasibility builds and site-directed attachment.
Design check
Maleimide-thiol adduct stability, competing thiols, and potential need for stabilized linkages.
Research fit
Peptide–PNA constructs with accessible thiol chemistry.
CLASSIC COVALENT COUPLING
Amide coupling
Activated carboxyl and amine handles can be joined through a stable amide bond when click-compatible handles are not suitable.
Amine–PNA
+
Activated Peptide–COOH
→
Amide conjugate
Attachment handles
Primary amine and activated carboxyl group or active ester.
Key advantage
Stable linkage using established peptide chemistry.
Design check
Selective protection and control of competing amines or carboxyl groups to avoid mixtures.
Research fit
Custom conjugates where an amide linkage matches the required architecture.
PROGRAM-SPECIFIC RELEASE
Cleavable linker designs
Cleavable spacers may be evaluated when a research program calls for a stimulus-responsive separation of peptide and PNA.
Peptide
—
Cleavable linker
—
PNA
Representative option
Disulfide linkages for reduction-responsive research designs.
Key advantage
Enables investigation of linker cleavage under defined conditions.
Design check
Cleavage conditions, premature instability, component compatibility, and analytical confirmation.
Research fit
Studies that explicitly require release rather than permanent linkage.
STABLE MOLECULAR ASSEMBLY
Non-cleavable linker designs
Non-cleavable linkages are appropriate when peptide and PNA should remain connected during the intended experiment.
Peptide
—
Stable linker
—
PNA
Representative options
Stable thioether, triazole, or amide connections, depending on coupling route.
Key advantage
Supports intact conjugate tracking, analytical controls, and stable assembly.
Design check
Solubility, steric separation, attachment position, and application-specific stability.
Research fit
Affinity, imaging, nanoparticle assembly, and stable CPP–PNA research constructs.