L Greenfield et al.
Bioconjugate chemistry, 1(6), 400-410 (1990-11-01)
Ricin A chain immunotoxins disulfide cross-linked with conventional, sterically unhindered reagents have unsatisfactorily short circulating life times in vivo. (Acetylthio)succinic anhydride, a thiolating reagent with partial steric hindrance of the sulfur atom, does not remedy this situation. Sulfosuccinimidyl N-[3-(acetylthio)-3-methylbutyryl]-beta- alaninate