py-maa-val-cit-pab-mmae

Py-MAA-Val-Cit-PAB-MMAE is a linker–payload intermediate developed by Chongqing Sintaho for the construction of antibody–drug conjugates (ADCs). This chemical construct consists of the cytotoxic payload monomethyl auristatin E (MMAE), a potent antimitotic agent that inhibits tubulin polymerization, conjugated to a cathepsin-cleavable Val-Cit-PAB (valine-citrulline-p-aminobenzyloxycarbonyl) linker. The Py-MAA (likely pyridine-maleimidoacetic acid) moiety serves as the conjugation handle for attachment to targeting antibodies. The Val-Cit-PAB linker is designed to remain stable in systemic circulation and undergo selective enzymatic cleavage by lysosomal proteases within target cancer cells, thereby releasing the active MMAE payload to induce cell cycle arrest and apoptosis.