Creative Biolabs offers our expertise in the generation of IgG-IgG bispecific antibodies (BsAbs), one format of BsAb conjugates, which is generated by conjugating two different whole antibodies together to get a 300kDa bispecific molecule with bivalent binding capability for each antigen.
Figure: Diagram of IgG-IgG BsAb (Drug Discov Today, 2015)
The process of IgG-IgG conjugation, which is the crosslinking of intact IgGs, is a common and direct approach for synthesizing BsAb. The generation of this type BsAb usually relies on amino-reactive reagents which target lysine side-chains, and the crosslinkers used to conjugate IgG-IgG are hetero-bifunctional in general. The most extensively used amino-reactive crosslinkers include SPDP (succinimidyl-3(2-pyridylthiol) propionate) and Traut’s reagent (2-iminothiolane)/ Sulpho-SMCC (sulpho-[succinimidyl-4-(N-maleimidomethyl)-4-cyclohexane-1-carboxylate]). In the two strategies, different antibodies are incubated separately with same or different reagents. Subsequently, co-incubation of these two modiﬁed antibodies can lead to generating the BsAbs linked by a reducible disulﬁde bond or a non-reducible thioether bond respectively. However, in the strategy that the antibodies conjugate using SPDP, an additional step is needed, which is adding DTT into a low pH reaction system during the last incubation step so as to cleave the crosslinker’s internal disulﬁde and get the sulfhydryl activated protein.
Scientists from Creative Biolabs have years of experience in generating BsAbs, therefore, we can provide high quality and cost effective services for different BsAbs formats, such as bispecific antibody conjugates, IgG-IgG BsAb, cov-X-Body, scFv1-PEG-scFv2 BsAb, to meet your every specific requirements.
For research use only. Not intended for any clinical use.