title: Binding and internalization of ricin labelled with fluorescein isothiocyanate.
abstract: The toxic lectin ricin has been covalently labelled with fluorescein isothiocyanate on the enzymatically active A chain. The fluorescein reacted toxin maintains its biological activity. The lateral diffusion coefficient of cell surface bound ricin, studied in two cell lines by fluorescence photobleaching recovery, is D = 1 - 2 x 10(-10) cm2/s. Fluorescence microscopy provides preliminary evidence for secondary endosomes in the cytoplasm.
authors.affiliation: Dipartimento di Scienze Biochimiche e Centro di Biologia Molecolare del C.N.R., Universita di Roma La Sapienza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bellelli
authors.forename: R
authors.initials: R
authors.lastname: Ippoliti
authors.forename: M
authors.initials: M
authors.lastname: Brunori
authors.forename: Z
authors.initials: Z
authors.lastname: Kam
authors.forename: M
authors.initials: M
authors.lastname: Benveniste
authors.forename: F
authors.initials: F
authors.lastname: Emmanuel
authors.forename: E
authors.initials: E
authors.lastname: Turpin
authors.forename: A
authors.initials: A
authors.lastname: Alfsen
authors.forename: J P
authors.initials: JP
authors.lastname: Frénoy
mesh_terms: D000818:Animals; D001692:Biological Transport; D002470:Cell Survival / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D004705:Endocytosis; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006386:Hemagglutination Tests; D006801:Humans; D007700:Kinetics; D008114:Liver Neoplasms, Experimental; D046911:Macromolecular Substances; D011485:Protein Binding; D051381:Rats; D012276:Ricin / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D013861:Thiocyanates; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; D046911:Macromolecular Substances; D013861:Thiocyanates; D012276:Ricin; D016650:Fluorescein-5-isothiocyanate