DM4-SPDP is a drug-linker conjugate composed of a potent antitubulin agent DM4 and a linker SMCC to make antibody drug conjugate[1]. SPDP is a short-chain crosslinker for amine-to-sulfhydryl conjugation via NHS-ester and pyridyldithiol reactive groups that form cleavable (reducible) disulfide bonds with cysteine sulfhydryls[2][3].
[1]. Tang R, et al. P-gp activity is a critical resistance factor against AVE9633 and DM4 cytotoxicity in leukaemia cell lines, but not a major mechanism of chemoresistance in cells from acute myeloid leukaemia patients. BMC Cancer. 2009 Jun 23;9:199. [2]. Lobedanz S et al. A periplasmic coiled-coil interface underlying TolC recruitment and the assembly of bacterial drug effluxpumps. Proc Natl Acad Sci U S A, 2007 Mar 13, 104(11):4612-7. [3]. Karumuthil-Melethil S et al. Dendritic cell-directed CTLA-4 engagement during pancreatic beta cell antigen presentation delays type 1diabetes. J Immunol 2010 Jun 15, 184(12):6695-708.