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Antibody Conjugates

Antibody conjugates are foundational in academic research and pharma, from antibody-drug conjugates to antibody-cytokine or antibody-reporter conjugates.

Connectase attaches drugs, labels or proteins to the C-termini of Lock-tagged heavy and/or light chains, producing homogeneous conjugates with a defined drug-to-antibody ratio instead of heterogeneous mixtures.

How the Connectase reaction works

Experimental data

Mass spectra of an antibody before and after conjugation
SDS gel of an antibody conjugation over time

a Mass spectrum of an antibody before (left) and after conjugation (right) with a test protein (Ubiquitin). The conjugation reaction replaces an affinity tag (S, Strep-tag) used to purify the antibody. The antibody peak shifts completely, indicating a fully labelled product.b SDS-PAGE time course of the antibody heavy chain (HC) conjugation reaction.

How to use

  1. Produce your antibody with Lock-tagged heavy and/or light chains.

  2. Produce a Key-tagged labelling partner (drug or protein).

  3. Mix with the Connectase ligation reagent and incubate for 1 hour.

Lock-Tag
ELASKDPGAFDADPLVVEI
C-terminal, 19 aa
Key-Tag
AGAFDADPLVVEI
N-terminal, 13 aa

Resources

FAQ

Do I need a spacer between the tag and my protein?
For sterically demanding proteins, we recommend an extra arginine (R) N-terminal to the Lock-Tag and two extra alanines (AA) C-terminal to the Key-Tag. Many other conjugations work efficiently without any additional linker sequence.
Which buffers does Connectase work in?
Connectase works over a wide pH and salt range and tolerates common additives such as detergents and chaotropes. It has no special buffer requirements.
How long do I need to incubate?
Most reactions are finished after about one hour at room temperature. Higher temperatures speed up the reaction.
Do I need to remove the enzyme after the reaction?
In most cases, no. Connectase is used at low concentrations and catalyzes nothing beyond the conjugation. Where removal is needed, its His-tag allows capture on Ni-NTA resin.

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