Step 1: The 19 aa Lock-Tag binds in the Connectase enzymatic tunnel.
- Short Tag
- Highest Specificity
- Fast at Low Concentrations
Bioconjugation is Fundamental in Biotechnology
Protein-protein fusions
Labelling & detection
Surface immobilization
Bioconjugation is the foundation of modern research and next-generation therapeutic conjugates. Yet the field is still dominated by chemical methods, which cannot modify complex proteins completely and site-specifically at once. Multi-step processes get closer, but they cost time and effort, and the underlying problem persists. This is a biological problem, and it calls for a biological answer. Yet the biological tools available so far cannot replace chemistry: they leave extra structures at the fusion site, or they struggle with side reactions and reversibility. The field is missing the one enzyme that ligates two fusion partners and nothing else.
What conventional methods deliver instead
Current conjugation methods yield heterogeneous products, compromising both R&D and drug development. A typical reaction gives a mixture: conjugates with different numbers of payloads at different positions, alongside leftover starting material and by-products. Four problems cause this:
Incomplete
The reaction is reversible, or side reactions necessitate an early stop, leaving sites unconjugated. Some molecules carry fewer payloads or none, and free payload has to be removed.
Non-specific
Conjugation occurs at several sites, so the number and position of payloads vary from molecule to molecule.
Unstable bond
Common linkages, such as maleimide-thiol bonds, can come apart in the blood and release the payload before it reaches its target.
Side reactions
Competing reactions alter the conjugation site, leaving it permanently unavailable for conjugation.
Connectase, nature's only dedicated protein ligase, changes this: it connects two molecules with absolute specificity, every time, and finishes the job with up to 100% yield and no side products. Whether you're running experiments with our research kits, building homogeneous antibody conjugates or trying to connect any other two molecules, Connectase makes bioconjugation fast, clean and reliable.
How Connectase works
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Step 2: It is locked via a hydrolysis-resistant amide bond.
- No Side Reactions
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Step 3: A 13 aa tag fragment is removed and digested.
- Complete 1:1 Conjugation
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Step 4: The 13 aa Key-Tag is fused to the Lock-Tag, releasing the product.
- Stable Bond
Why Connectase
Complete 1:1 conjugation
The reaction is free of side reactions and thermodynamically driven, resulting in up to 100% fusion product.
Highest specificity
The 19 aa Connectase recognition sequence is unique in every sample, ensuring absolute specificity.
Stable bond
A regular peptide bond is created between the fusion partners.
No side reactions
Connectase uses a reaction mechanism that sets it apart from all other transpeptidases and creates no side products.
Short tags
The fusion reaction needs only short tags on the reaction partners and leaves a 19 aa linker between them.
Fast at low concentrations
Connectase binds its substrates with nanomolar affinity, ensuring fast reactions even in very dilute solutions.
Compatible with all buffers
Connectase works over a wide pH and ionic strength range and tolerates additives such as detergents or chaotropes. It has no special buffer requirements.
Biological & chemical substrates
The reaction requires only a short tag that can be genetically encoded or chemically synthesized.
Published science
- Enzymatic protein fusions with 100% product yield (opens the article at the publisher)
- Detection and quantification of C-terminally tagged proteins by in-gel fluorescence (opens the article at the publisher)
- Specific, sensitive and quantitative protein detection by in-gel fluorescence (opens the article at the publisher)
- Archaeal Connectase is a specific and efficient protein ligase related to proteasome β subunits (opens the article at the publisher)