Extracellular Domain (ECD) Protein

Extracellular domain proteins (ECD proteins) are regions of membrane proteins located outside the cell membrane and are essential for signal recognition, ligand binding, and cell–cell communication. Many key drug targets, including GPCRs, RTKs, and immune checkpoints such as PD-1 and CTLA-4, depend on their extracellular domains for biological function. ECDs play critical roles in immune regulation, tumorigenesis, and viral infection. As full-length membrane proteins are difficult to stabilize, soluble recombinant ECDs, generated by removing transmembrane regions, are widely used in membrane protein research and drug screening, including ELISA, SPR, and antibody discovery assays.

DIMA BIOTECH focuses on ECD proteins from single-pass membrane proteins and has successfully expressed1,600+ high-purity ECDs covering more than 900 targets, including GPCRs, immune checkpoints, tumor antigens, and metabolic receptors. 500+ targets are supported by matched flow cytometry antibodies. All ECD proteins are validated by SDS-PAGE for purity and ELISA for activity, enabling antibody screening, functional studies, and structural research in membrane protein drug development.

View All ECD Proteins

Application of ECD

Primary antibody screening
Antibody affinity comparison and ranking
Epitope binning and mechanism-of-action studies
ELISA / SPR / BLI assay development
Pre-validation before cell or full-length protein assays

Why Choose DIMA BIOTECH

Mammalian expression, stable conformation
Multi-species & multi-domain, in stock
1,600+ ECDs, 900+ drug targets
Flow antibody–ready, 500+ projects validated
Broad applications, faster antibody discovery

Hot Druggable Targets

Immune checkpoint proteins

Immune checkpoint proteins (such as PD-1, CTLA-4, and PD-L1) are molecules that regulate immune responses, often by suppressing immune activity to maintain self-tolerance and prevent autoimmunity.

More immune checkpoints

Hematological cancer targets

Hematological cancer targets (such as CD19, CD20, and CD38) are specific molecules involved in blood cancers like leukemia, lymphoma, and myeloma, which are used for targeted therapies such as monoclonal antibodies.

More hematological cancer

Solid tumor targets

Solid tumor targets (such as HER2, EGFR, and VEGF) are specific molecules found on the surface of solid tumor cells, such as in breast, lung, and colorectal cancers, which are targeted by therapies like monoclonal antibodies and small molecules.

More solid tumor targets

ECD Validated Data

Human 4-1BB(46-86) Protein (PME101695)

Mouse 4-1BB Protein (PME-M100007)

Cynomolgus 4-1BB Protein (PME-C100023)

ELISA plate pre-coated by 2 μg/ml (100 μl/well) Human CS1 protein (PME100002) can bind Anti-CS1 Neutralizing antibody BME100002 in a linear range of 7.81-210.7 ng/ml.

ELISA plate pre-coated by 2 μg/ml (100 μl/well) Human BCMA protein (PME100001) can bind Anti-BCMA Neutralizing antibody (BME100016) in a linear range of 3.71-22.29 ng/ml.

Loaded Anti-MUC1 mAb (BME100249) on Pro-A Biosensor, can bind Human MUC1 Protein (PME100106) with an affinity constant of 0.432nM.

Loaded Anti-ACVR2B mAb (BME100228) on Pro-A Biosensor binds Human ACVR2B Protein (PME101717) with an afinity constant of 0.169nM.

HEK293 cell line transfected with irrelevant protein (B) and human B7-2 (A) were surface stained with Human CD28 protein (PME100014) 1μg/ml followed by Alexa 488-conjugated anti-mouse IgG secondary antibody.

HEK293 cell line transfected with irrelevant protein (B) and human GITR Ligand (A) were surface stained with Human GITR protein (PME100019) 1μg/ml followed by Alexa 488-conjugated anti-mouse IgG secondary antibody.

Click to view activity and stability testing data