title: Thiol-containing cross-linking agent with enhanced steric hindrance.
abstract: 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, a new cross-linker in which the carbon alpha to the sulfur is doubly methylated, creates disulfide bonds 2 orders of magnitude more resistant to reduction than unhindered disulfides. Nevertheless, this deactivated thiolating agent rapidly and reliably cross-links ricin A chain and antibodies to create immunotoxins with in vitro cytotoxicities comparable to those of 2-iminothiolane-coupled conjugates.
authors: PCR Department, Cetus Corporation, Emeryville, California 94608.
authors: L
authors: L
authors: Greenfield
authors: W
authors: W
authors: Bloch
authors: M
authors: M
authors: Moreland
mesh_terms: D000906:Antibodies; D001943:Breast Neoplasms / Q000188:drug therapy; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004355:Drug Stability; D004952:Esters / Q000737:chemistry; D006801:Humans; D006868:Hydrolysis; D000922:Immunotoxins / Q000138:chemical synthesis / Q000627:therapeutic use; D007202:Indicators and Reagents; D007700:Kinetics; D015394:Molecular Structure; D012276:Ricin; D013387:Succinic Anhydrides / Q000737:chemistry; D013388:Succinimides / Q000138:chemical synthesis / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014407:Tumor Cells, Cultured; D015091:beta-Alanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000906:Antibodies; D003432:Cross-Linking Reagents; D004952:Esters; D000922:Immunotoxins; D007202:Indicators and Reagents; D013387:Succinic Anhydrides; D013388:Succinimides; D013438:Sulfhydryl Compounds; D015091:beta-Alanine; C069579:sulfosuccinimidyl-N-(3-(acetylthio)-3-methylbutyryl)-beta-alanine; C069578:N-(3-mercapto-3-methylbutyryl)-beta-alanine; C024249:S-acetylmercaptosuccinic anhydride; D012276:Ricin