Antibody-drug conjugates (ADCs) consist of a desirable monoclonal antibody, an active cytotoxic drug and an appropriate linker. An appropriate linker between the antibody and the cytotoxic drug provides a specific bridge, and thus helps the antibody to selectively deliver the cytotoxic drug to tumor cells and accurately releases the cytotoxic drug at tumor sites. In addition to conjugation, the linkers maintain ADCs’ stability during the preparation and storage stages of the ADCs and during the systemic circulation period. The ADCs currently undergoing clinical evaluation contain linkers are mostly classified into two categories: cleavable and noncleavable. Cleavable linkers rely on processes inside the cell to liberate the toxin, such as reduction in the cytoplasm, exposure to acidic conditions in the lysosome, or cleavage by specific proteases within the cell. Noncleavable linkers require proteolytic degradation of the antibody portion of the ADC for release of the cytotoxic molecule, which will retain the linker and the amino acid by which it was attached to the antibody. The selection of linker is target dependent, based on the knowledge of the internalization and degradation of the antibody-target antigen complex, and a preclinical in vitro and in vivo activity comparison of conjugates. Moreover, the choice of a linker is also influenced by which cytotoxin is used, as each molecule has different chemical constraints, and frequently the drug structure lends itself to a specific linker.


Anti-infection >
Arenavirus Bacterial CMV Enterovirus Filovirus Fungal HBV HCV HIV HSV Influenza Virus Parasite Reverse Transcriptase RSV SARS-CoV
Antibody-drug Conjugate >
ADC Cytotoxin ADC Linker Drug-Linker Conjugates for ADC PROTAC-linker Conjugate for PAC
Apoptosis >
Apoptosis Bcl-2 Family c-Myc Caspase DAPK Ferroptosis IAP MDM-2/p53 PKD RIP kinase Survivin Thymidylate Synthase TNF Receptor
Autophagy >
Autophagy LRRK2 ULK Mitophagy
Cell Cycle/DNA Damage >
Antifolate APC ATM/ATR Aurora Kinase Casein Kinase CDK Checkpoint Kinase (Chk) CRISPR/Cas9 Deubiquitinase DNA Alkylator/Crosslinker DNA-PK DNA/RNA Synthesis Eukaryotic Initiation Factor (eIF) G-quadruplex Haspin Kinase HDAC HSP IRE1 Kinesin LIM Kinase (LIMK) Microtubule/Tubulin Mps1 Nucleoside Antimetabolite/Analog p97 PAK PARP PERK Polo-like Kinase (PLK) PPAR RAD51 ROCK Sirtuin SRPK Telomerase TOPK Topoisomerase Wee1
Cytoskeleton >
Arp2/3 Complex Dynamin Gap Junction Protein Integrin Kinesin Microtubule/Tubulin Mps1 Myosin PAK
Epigenetics >
AMPK Aurora Kinase DNA Methyltransferase Epigenetic Reader Domain HDAC Histone Acetyltransferase Histone Demethylase Histone Methyltransferase JAK MicroRNA PARP PKC Sirtuin Protein Arginine Deiminase
GPCR/G Protein >
5-HT Receptor Adenosine Receptor Adenylate Cyclase Adiponectin Receptor Adrenergic Receptor Angiotensin Receptor Bombesin Receptor Bradykinin Receptor Cannabinoid Receptor CaSR CCR CGRP Receptor Cholecystokinin Receptor CRFR CXCR Dopamine Receptor EBI2/GPR183 Endothelin Receptor GHSR Glucagon Receptor Glucocorticoid Receptor GNRH Receptor GPCR19 GPR109A GPR119 GPR120 GPR139 GPR40 GPR55 GPR84 Guanylate Cyclase Histamine Receptor Imidazoline Receptor Leukotriene Receptor LPL Receptor mAChR MCHR1 (GPR24) Melatonin Receptor mGluR Motilin Receptor Neurokinin Receptor Neuropeptide Y Receptor Neurotensin Receptor Opioid Receptor Orexin Receptor (OX Receptor) Oxytocin Receptor P2Y Receptor Prostaglandin Receptor Protease-Activated Receptor (PAR) Ras RGS Protein Sigma Receptor Somatostatin Receptor TSH Receptor Urotensin Receptor Vasopressin Receptor Melanocortin Receptor
Immunology/Inflammation >
Aryl Hydrocarbon Receptor CCR Complement System COX CXCR FLAP Histamine Receptor IFNAR Interleukin Related IRAK MyD88 NO Synthase NOD-like Receptor (NLR) PD-1/PD-L1 PGE synthase Salt-inducible Kinase (SIK) SPHK STING Thrombopoietin Receptor Toll-like Receptor (TLR) Arginase
JAK/STAT Signaling >
EGFR JAK Pim STAT
MAPK/ERK Pathway >
ERK JNK KLF MAP3K MAP4K MAPKAPK2 (MK2) MEK Mixed Lineage Kinase MNK p38 MAPK Raf Ribosomal S6 Kinase (RSK)
Membrane Transporter/Ion Channel >
ATP Synthase BCRP Calcium Channel CFTR Chloride Channel CRAC Channel CRM1 EAAT2 GABA Receptor GlyT HCN Channel iGluR Monoamine Transporter Monocarboxylate Transporter Na+/Ca2+ Exchanger Na+/HCO3- Cotransporter Na+/K+ ATPase nAChR NKCC P-glycoprotein P2X Receptor Potassium Channel Proton Pump SGLT Sodium Channel TRP Channel URAT1
Metabolic Enzyme/Protease >
15-PGDH 5 alpha Reductase 5-Lipoxygenase Acetyl-CoA Carboxylase Acyltransferase Adenosine Deaminase Adenosine Kinase Aldehyde Dehydrogenase (ALDH) Aldose Reductase Aminopeptidase Angiotensin-converting Enzyme (ACE) ATGL ATP Citrate Lyase Carbonic Anhydrase Carboxypeptidase Cathepsin CETP COMT Cytochrome P450 Dipeptidyl Peptidase Dopamine β-hydroxylase E1/E2/E3 Enzyme Elastase Enolase FAAH FABP Factor Xa Farnesyl Transferase Fatty Acid Synthase (FAS) FXR Glucokinase GSNOR Gutathione S-transferase HCV Protease Hexokinase HIF/HIF Prolyl-Hydroxylase HIV Integrase HIV Protease HMG-CoA Reductase (HMGCR) HSP Indoleamine 2,3-Dioxygenase (IDO) Isocitrate Dehydrogenase (IDH) Lactate Dehydrogenase LXR MAGL Mineralocorticoid Receptor Mitochondrial Metabolism MMP Nampt NEDD8-activating Enzyme Neprilysin PAI-1 PDHK PGC-1α Phosphatase Phosphodiesterase (PDE) Phospholipase Procollagen C Proteinase Proteasome Pyruvate Kinase RAR/RXR Renin ROR Ser/Thr Protease SGK Stearoyl-CoA Desaturase (SCD) Thrombin Tryptophan Hydroxylase Tyrosinase Xanthine Oxidase
Neuronal Signaling >
5-HT Receptor AChE Adenosine Kinase Amyloid-β Beta-secretase CaMK CGRP Receptor COMT Dopamine Receptor Dopamine Transporter FAAH GABA Receptor GlyT iGluR Imidazoline Receptor mAChR Melatonin Receptor Monoamine Oxidase nAChR Neurokinin Receptor Opioid Receptor Serotonin Transporter γ-secretase
NF-κB >
NF-κB IKK Keap1-Nrf2 MALT1
PI3K/Akt/mTOR >
Akt AMPK ATM/ATR DNA-PK GSK-3 MELK mTOR PDK-1 PI3K PI4K PIKfyve PTEN
PROTAC >
PROTAC E3 Ligase Ligand-Linker Conjugate Ligand for E3 Ligase PROTAC Linker PROTAC-linker Conjugate for PAC
Protein Tyrosine Kinase/RTK >
Ack1 ALK Bcr-Abl BMX Kinase Btk c-Fms c-Kit c-Met/HGFR Discoidin Domain Receptor DYRK EGFR Ephrin Receptor FAK FGFR FLT3 IGF-1R Insulin Receptor IRAK Itk PDGFR PKA Pyk2 ROS Src Syk TAM Receptor Trk Receptor VEGFR
Stem Cell/Wnt >
Casein Kinase ERK Gli GSK-3 Hedgehog Hippo (MST) JAK Notch Oct3/4 PKA Porcupine ROCK sFRP-1 Smo STAT TGF-beta/Smad Wnt YAP β-catenin γ-secretase
TGF-beta/Smad >
TGF-beta/Smad PKC ROCK TGF-β Receptor
Vitamin D Related >
VD/VDR
Others >
Androgen Receptor Aromatase Estrogen Receptor/ERR Progesterone Receptor Thyroid Hormone Receptor Others

DBCO-PEG3 acetic-EVCit-PAB

DBCO-PEG4 acetic-EVCit-PAB is a cleavable 4 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 2253947-17-8
  • MF: C54H72N8O13
  • MW: 1041.20
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Fomc-Gly-Gly-Phe-Gly-OH

Fomc-Gly-Gly-Phe-Gly-OH (compound D5) can be used as an intermediate in the synthesis of ADC dual-drug-linker. Fomc-Gly-Gly-Phe-Gly-OH synthetic intermediate GGFGE further forms an important ADC dual-drug link assembly unit[1].

  • CAS Number: 1817857-75-2
  • MF: C30H30N4O7
  • MW: 558.58
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Vipivotide tetraxetan Linker

Vipivotide tetraxetan Linker is a useful peptide linker for synthesis of Vipivotide tetraxetan (PSMA-617). Vipivotide tetraxetan (PSMA-617) is a ligand used to synthesize 177Lu-PSMA-617, which is a radioactive molecule for the treatment of prostate cancer[1].

  • CAS Number: 1703768-74-4
  • MF: C33H45N5O9
  • MW: 655.74
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

m-PEG3-CH2CH2COOH

m-PEG3-CH2CH2COOH is a non-cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs).

  • CAS Number: 67319-28-2
  • MF: C10H20O6
  • MW: 236.262
  • Catalog: ADC Linker
  • Density: 1.1±0.1 g/cm3
  • Boiling Point: 352.3±32.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 129.8±18.6 °C

NMS-P945

NMS-P945 is an ADC linker that can be used in the synthesis of antibody-drug conjugates (ADCs). NMS-P945 is suitable for conjugation to mAbs with reproducible Drug Antibody Ratio (DAR) >3.5[1].

  • CAS Number: 1466546-35-9
  • MF: C61H76ClN11O12S
  • MW: 1222.84
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Maleimido-tri(ethylene glycol)-propionic acid

Maleimido-tri(ethylene glycol)-propionic acid is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs). Maleimido-tri(ethylene glycol)-propionic acid is used for the preparation of neolymphostin-based ADC precursors for site-specific cysteine mutant trastuzumab-A114C conjugation[1].

  • CAS Number: 518044-40-1
  • MF: C13H19NO7
  • MW: 301.293
  • Catalog: ADC Linker
  • Density: 1.5±0.1 g/cm3
  • Boiling Point: 634.2±55.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 337.3±31.5 °C

N-Boc-PEG4-bromide

N-Boc-PEG5-bromide is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 1392499-32-9
  • MF: C15H30BrNO6
  • MW: 400.31
  • Catalog: ADC Linker
  • Density: 1.223±0.06 g/cm3
  • Boiling Point: 459.3±40.0 °C
  • Melting Point: N/A
  • Flash Point: N/A

UAA crosslinker 1

UAA crosslinker 1 act as substrates for pylRS/tRNA pair that enable its incorporation into a target protein.

  • CAS Number: 1167421-25-1
  • MF: C9H17N5O4
  • MW: 259.26200
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

N-Succinimidyl 6-maleimidohexanoate

6-Maleimidohexanoic acid N-hydroxysuccinimide ester(ECMS) is a useful protective group in antibody drug conjugates.

  • CAS Number: 55750-63-5
  • MF: C14H16N2O6
  • MW: 308.287
  • Catalog: ADC Linker
  • Density: 1.4±0.1 g/cm3
  • Boiling Point: 480.6±47.0 °C at 760 mmHg
  • Melting Point: 70-73 °C(lit.)
  • Flash Point: 244.5±29.3 °C

H2N-PEG8-CH2CH2COO<sup>t</sup>Bu

Amino-PEG8-Boc is a cleavable 8 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 756526-06-4
  • MF: C23H47NO10
  • MW: 497.62000
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

SMPT

SMPT is a non-cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 112241-19-7
  • MF: C18H16N2O4S2
  • MW: 388.46100
  • Catalog: ADC Linker
  • Density: 1.43g/cm3
  • Boiling Point: 547ºC at 760mmHg
  • Melting Point: N/A
  • Flash Point: 284.6ºC

Amino-PEG11-OH

Amino-PEG11-OH is non-cleavable 11 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 15332-94-2
  • MF: C22H47NO11
  • MW: 501.61
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

N-Succinimidyl 3-maleimidopropionate

BMPS is a nonclaevable ADC linker used in the synthesis of antibody-drug conjugates (ADCs).

  • CAS Number: 55750-62-4
  • MF: C11H10N2O6
  • MW: 266.20700
  • Catalog: ADC Linker
  • Density: 1.55g/cm3
  • Boiling Point: 448.8ºC at 760mmHg
  • Melting Point: 168-170 °C(lit.)
  • Flash Point: 225.2ºC

N-Succinimidyl maleimidoacetate

AMAS is a heterobifunctional crosslinker with NHS ester and maleimide groups that allows covalent conjugation of amine- and sulfhydryl-containing molecules.

  • CAS Number: 55750-61-3
  • MF: C10H8N2O6
  • MW: 252.180
  • Catalog: ADC Linker
  • Density: 1.6±0.1 g/cm3
  • Boiling Point: 430.1±47.0 °C at 760 mmHg
  • Melting Point: 174-175ºC
  • Flash Point: 213.9±29.3 °C

Glucocorticoid receptor agonist-1 phosphate Gly-Glu TFA

Glucocorticoid receptor agonist-1 phosphate Gly-Glu (TFA) is a cleavable linker, that can be used to synthesize Antibody-Drug Conjugates (ADCs).

  • CAS Number: 2734877-83-7
  • MF: C44H51F3N3O15P
  • MW: 949.86
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

CL2 Linker

CL2 Linker is an ADC linker. CL2-SN-38 and CL2A-SN-38 are equivalent in drug substitution (~6), cell binding (Kd ~1.2 nM), cytotoxicity (IC50 ~2.2 nM), and serum stability in vitro (t1/2 ~20 hours)[1][2].

  • CAS Number: 2270986-66-6
  • MF: C68H103N11O22
  • MW: 1426.61
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Bis-PEG5-NHS ester

Bis-PEG5-NHS ester is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 756526-03-1
  • MF: C22H32N2O13
  • MW: 532.49500
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

CCK2R Ligand-Linker Conjugates 1

CCK2R ligand CRL is a ligand-linker conjugate; which conjugates to the cytotoxic antimicrotubule agents Desacetyl Vinblastine Hydrazide (DAVBH) and Tubulysin B Hydrazide (TubBH) via a hydrophilic peptide linker[1].

  • CAS Number: 1452145-13-9
  • MF: C72H110N12O27S
  • MW: 1607.77
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Biotin-PEG4-PFP ester

Biotin-PEG4-PFP ester is a cleavable 4 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 1334172-58-5
  • MF: C27H36F5N3O8S
  • MW: 657.647
  • Catalog: ADC Linker
  • Density: 1.3±0.1 g/cm3
  • Boiling Point: 804.9±65.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 440.6±34.3 °C

Aminooxy-PEG2-azide

Aminooxy-PEG2-azide is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs[1]. Aminooxy-PEG2-azide is also a non-cleavable 2 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[2].

  • CAS Number: 1043426-13-6
  • MF: C6H14N4O3
  • MW: 190.20
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Me-Tet-PEG2-NHS

Me-Tet-PEG2-NHS is an ADC Linker containing 2 PEG units. Me-Tet-PEG2-NHS can utilize its own Tetrazine group to undergo a specific inverse electron demand Diels-Alder reaction (iEDDA) with compounds with TCO groups.

  • CAS Number: 2740357-12-2
  • MF: C23H28N6O7
  • MW: 500.50
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

NH2-PEG6-Boc

NH2-PEG6-Boc is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs[1]. NH2-PEG6-Boc is also a non-cleavable 6 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[2].

  • CAS Number: 1286281-32-0
  • MF: C19H39NO8
  • MW: 409.51500
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

NH2-PEG9-acid

NH2-PEG9-acid is a non-cleavable 9 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 756526-04-2
  • MF: C19H39NO10
  • MW: 441.514
  • Catalog: ADC Linker
  • Density: 1.1±0.1 g/cm3
  • Boiling Point: 547.1±50.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 284.7±30.1 °C

Fmoc-N-amido-PEG8-acid

Fmoc-NH-PEG8-CH2CH2COOH is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 756526-02-0
  • MF: C34H49NO12
  • MW: 663.75200
  • Catalog: ADC Linker
  • Density: 1.190±0.06 g/cm3
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

3-Azidopropionic Acid Sulfo-NHS Ester

3-Azidopropionic Acid Sulfo-NHS ester is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 2055198-09-7
  • MF: C7H7N4NaO7S
  • MW: 314.21
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Bis-PEG13-NHS ester

Bis-PEG13-NHS ester is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 2221949-00-2
  • MF: C38H64N2O21
  • MW: 884.92
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

m-PEG3-Amine

m-PEG3-Amine is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 74654-07-2
  • MF: C7H17NO3
  • MW: 163.21500
  • Catalog: ADC Linker
  • Density: 0.978g/cm3
  • Boiling Point: 223.9ºC at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 86.1ºC

Azidoethyl-SS-propionic acid

Azidoethyl-SS-propionic acid is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 2228857-32-5
  • MF: C5H9N3O2S2
  • MW: 207.27
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Propargyl-PEG6-NHS ester

Propargyl-PEG6-NHS ester is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 2093153-99-0
  • MF: C20H31NO10
  • MW: 445.46
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Amino-ethyl-SS-PEG3-NHBoc

Amino-ethyl-SS-PEG3-NHBoc is a cleavable 3 unit PEG ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].

  • CAS Number: 2144777-87-5
  • MF: C15H32N2O5S2
  • MW: 384.55
  • Catalog: ADC Linker
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A