A therapeutic antibody’s efficacy is dependent not only on the Fab fragment and its binding activity to the target antigen but also on the Fc fragment and its interaction with key Fc receptors.
The binding affinity of the Fc fragment towards FcRn (FCGRT&B2M) would help forecast the half-life of the antibody, while that between the Fc fragment and FcγRIIIa (CD16a) would impact the potential of the antibody to evoke antibody-dependent cell-mediated cytotoxicity (ADCC). Thus, candidates should be tested against a panel of receptors at the time of antibody engineering.
ACROBiosystems provides an extensive collection of recombinant Fc receptor proteins, which includes their common variants, to help accelerate the mAb development of users.
Hot targets
-1.jpg)
Image Credit: ACROBiosystems
Benefits of Fc receptor protein products
- Expressed by HEK293 Cells: post-translational modification and proper protein folding can be done
- High stability: strict quality control to guarantee high batch-to-batch consistency
- High purity: SDS-PAGE verification purity of >95%, SEC-MALS verification purity of >90%
- Multiple species: Human, Mouse, Cynomolgus/Rhesus macaque, Rat, Rabbit, Porcine, Bovine, Feline, can be completely employed in various cross species experiments
- Low endotoxin: ＜1.0 EU/µg
- Affinity verified by SPR and BLI: activity guaranteed, and protocols provided with no charge
- Biotinylated Fc Receptor proteins labeled with AvitagTM offered: the labeling efficiency is high, and the labeling site is particular and clear, appropriate for BLI/SPR/ELISA detection depending on binding to streptavidin in the process of drug development and optimization process
Key features
High purity
To address the high purity demands of pharmaceutical applications, the ACROBiosystems production team executes both SDS-PAGE and SEC-MALS analyses of the Fc receptors for QC purposes.
It is highly necessary to utilize the monomeric Fc receptor, which constitutes its natural state. The formation of oligomers during production might lead to artificially improved binding interaction as a result of the avidity effect.
For such a situation to be avoided, ACROBiosystems has established rigorous internal control standards of monomer purity by SEC-MALS testing. Only those batches that fulfill all purity needs are launched.
Figure 1. The purity of Human CD32a (R167), His Tag (Cat. No. CDA-H5221) is more than 95% verified by SDS-PAGE. The purity of Human CD32a (R167), His Tag (Cat. No. CDA-H5221) is more than 90% verified by SEC-MALS. And the molecular weight of this protein is around 25–35 kDa. Image Credit: ACROBiosystems
Bioactivity validated by SPR&BLI
Several techniques can help find the binding affinity between two molecules. But the studies of Fc interaction are frequently performed by SPR. This is because conventional ELISA is not suitable for low-affinity receptors like CD16 and CD32.
To ensure Fc receptors from ACROBiosystems deliver anticipated performance, the company’s QC team utilizes the Biacore platform to test the products against reference antibodies. Besides, to satisfy more applications in the development of antibody drugs, the QC team also utilizes the ForteBio platform to test the products against reference antibodies.
Figure 2. Human CD64, His Tag (SPR & BLI verified) (Cat. No. FCA-H52H1) captured on CM5 chip via anti-His antibody can bind Herceptin with an affinity constant of 4.92 nM as determined in an SPR assay (Biacore 8K) (QC tested). Image Credit: ACROBiosystems
Figure 3. Immobilized Human FCGRT&B2M Heterodimer Protein, His Tag&Strep II Tag (SPR & BLI verified) (Cat. No. FCM-H5286) on CM5 Chip via Anti-His antibody, can bind Herceptin with an affinity constant of 0.261 μM as determined in an SPR assay (Biacore T200). Image Credit: ACROBiosystems
Figure 4. Loaded Human CD64, His Tag (SPR & BLI verified) (Cat. No. FCA-H52H1) on HIS1K Biosensor, can bind Herceptin with an affinity constant of 6.98 nM as determined in BLI assay (ForteBio Octet Red96e). Image Credit: ACROBiosystems
Figure 5. Loaded Human FCGRT&B2M Heterodimer Protein, His Tag (SPR & BLI verified) (Cat. No. FCN-H52W7) on SA Biosensor via Biotin his antibody, can bind Herceptin with an affinity constant of 0.14 μM as determined in BLI assay (ForteBio Octet Red96e). Image Credit: ACROBiosystems
High batch-to-batch consistency
ACROBiosystems routinely employs strict quality control measures to guarantee the consistent performance of the product. As displayed below, the batch variation among the tested samples is insignificant.
Figure 6. Immobilized Human Fc gamma RIIB / CD32b Protein (Cat. No. CDB-H5228) on CM5 Chip via anti-His antibody, can bind Rituximab with an affinity constant of 10 μM as determined in an SPR assay (Biacore T200). Image Credit: ACROBiosystems
ACROBiosystems has compared the performance of various batches of CD32b (CDB-H5228) in the same assay, and the software analysis displayed that the similarity score was very high, implying high batch-to-batch consistency.
Figure 7. Batch consistency of Human Fc gamma RIIB / CD32b (Cat. No. CDB-H5228). The consistency of different batches is more than 90%. Image Credit: ACROBiosystems
Biotinylated or other species Fc receptors available
Biotin labeling can render users’ assay development simpler. ACROBiosystems provides a range of ready-to-use biotinylated Fc receptors. Such proteins are generated with the help of the in-house developed labeling methods, which confer high bioactivity and least batch-to-batch variation. Besides, ACROBiosystems has designed a series of Fc receptors of other species, which are apt for the screening of the species cross-reaction or non-humanized antibodies.
Figure 8. Biotinylated Human CD16a (V176), His Tag, Avi Tag (Cat. No.CDA-H82E9) captured on Biotin CAP- Series S Sensor Chip can bind Rituximab with an affinity constant of 0.261 μM as determined in an SPR assay (Biacore T200). Image Credit: ACROBiosystems
Figure 9. Immobilized Cynomolgus / Rhesus macaque FcRn Protein (Cat. No. FCM-C5284) on CM5 Chip via anti-His antibody, can bind Herceptin with an affinity constant of 0.403 μM as determined in an SPR assay (Biacore T200). Image Credit: ACROBiosystems
Source: ACROBiosystems
| Molecule |
Cat. No. |
Host |
Product description |
Structure |
| FcRn (FCGRT & B2M) |
FCM-H5286 |
HEK293 |
Human FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Strep II Tag (SPR & BLI & MALS verified)Hot |
|
| FCM-H8286 |
HEK293 |
Biotinylated Human FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Strep II Tag, ultra sensitivity (primary amine labeling) (SPR verified) |
|
| FCM-H82W4 |
HEK293 |
Biotinylated Human FcRn / FCGRT&B2M Heterodimer Protein, Avitag™,His Tag&Strep II Tag (SPR & BLI & MALS verified)Hot |
|
| FCM-H82W7 |
HEK293 |
Biotinylated Human FcRn / FCGRT&B2M Heterodimer Protein, His,Avitag™ (MALS & SPR verified) |
|
| FCN-H52W7 |
HEK293 |
Human FcRn / FCGRT&B2M Heterodimer Protein, His Tag (SPR & BLI & MALS verified)Hot |
|
| FCM-M52W2 |
HEK293 |
Mouse FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Twin-Strep Tag (MALS & BLI verified) |
|
| FCM-M52W8 |
HEK293 |
Mouse FcRn / FCGRT&B2M Heterodimer Protein, His Tag (MALS & BLI verified) |
|
| FCM-M82W5 |
HEK293 |
Biotinylated Mouse FcRn / FCGRT&B2M Heterodimer Protein, His,Avitag™ (MALS & BLI verified) |
|
| FCM-M82W6 |
HEK293 |
Biotinylated Mouse FcRn / FCGRT&B2M Heterodimer Protein, Avitag™,His Tag&Twin-Strep Tag (MALS & BLI-verified) |
|
| FCM-R5287 |
HEK293 |
Rat FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Strep II Tag (MALS & SPR verified) |
|
| FCM-R82W7 |
HEK293 |
Biotinylated Rat FcRn / FCGRT&B2M Heterodimer Protein, Avitag™,His Tag&Strep II Tag (MALS & SPR verified) |
|
| FCM-R52W5 |
HEK293 |
Rabbit FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Tag Free (MALS & SPR verified) |
|
| FCM-C5284 |
HEK293 |
Cynomolgus / Rhesus macaque FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Strep II Tag (MALS & BLI verified) |
|
| FCM-C52W9 |
HEK293 |
Cynomolgus / Rhesus macaque FcRn / FCGRT&B2M Heterodimer Protein, His Tag (MALS & BLI verified) |
|
| FCM-C82W3 |
HEK293 |
Biotinylated Cynomolgus / Rhesus macaque FcRn / FCGRT&B2M Heterodimer Protein, His,Avitag™ (MALS & SPR verified) |
|
| FCM-C82W5 |
HEK293 |
Biotinylated Cynomolgus / Rhesus macaque FcRn Heterodimer Protein, His,Avitag™&Strep II Tag (SPR & BLI verified) |
|
| FCM-P5280 |
HEK293 |
Porcine FcRn / FCGRT&B2M Heterodimer Protein, His Tag&Strep II Tag (MALS & SPR verified) |
|
| FCN-F82W3 |
HEK293 |
Biotinylated Feline FcRn / FCGRT&B2M Heterodimer Protein, His,Avitag™ (MALS & SPR verified) |
|
| FCN-B82W3 |
HEK293 |
Biotinylated Bovine FcRn / FCGRT&B2M Heterodimer Protein, His,Avitag™ (MALS & SPR verified) |
|
(All Fc receptors are expressed from HEK293)
Fc receptor-related molecules — IgG Fc protein
- IgG Fc
- IgG1 Fc
- IgG2 Fc
- IgG2a Fc
- IgG2b Fc
- IgG4 Fc
- IgG3 Fc