{"entity":{"id":"sulfo-spdb","kind":"term","name":"Sulfo-SPDB (disulfide)","aka":["hindered disulfide linker"],"tldr":"Sulfo-SPDB is a hindered disulfide linker that is stable in blood but is cut by the reducing environment inside cells, then converted to a membrane-crossing form.","summary":"Sulfo-SPDB attaches DM4 via a sterically hindered disulfide with a charged sulfonate that improves solubility and reduces aggregation. Intracellular glutathione reduces the bond; the released thiol is S-methylated into a neutral metabolite that diffuses to neighbouring cells. Used in mirvetuximab soravtansine.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Mirvetuximab_soravtansine","links":[{"label":"Disulfide-linked antibody-maytansinoid conjugates incl. sulfo-SPDB (Kellogg et al., Bioconjugate Chem 2011)","url":"https://doi.org/10.1021/bc100480a"}],"tags":[],"related":["dm4"],"cancers":[],"sections":[],"technologies":["adc"],"targets":[],"drugs":["mirvetuximab-soravtansine"],"companies":[],"institutions":[],"pathways":[],"terms":["linker"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":["paper-kellogg-bioconjug-chem"],"journals":[],"dependsOn":[],"notes":[],"category":"ADC chemistry"},"route":"/terms/sulfo-spdb/","neighbours":{"term":[{"id":"dm4","kind":"term","name":"DM4","route":"/terms/dm4/"},{"id":"linker","kind":"term","name":"Linker (ADC)","route":"/terms/linker/"}],"technology":[{"id":"adc","kind":"technology","name":"Antibody-drug conjugate (ADC)","route":"/technologies/adc/"}],"drug":[{"id":"mirvetuximab-soravtansine","kind":"drug","name":"Mirvetuximab soravtansine","route":"/drugs/mirvetuximab-soravtansine/"}],"paper":[{"id":"paper-kellogg-bioconjug-chem","kind":"paper","name":"Disulfide-linked antibody-maytansinoid conjugates: optimization of in vivo activity by varying the steric hindrance at carbon atoms adjacent to the disulfide linkage","route":"/key-papers/paper-kellogg-bioconjug-chem/"}]}}