Binding and internalization of ricin labelled with fluorescein isothiocyanate.
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.
Bellelli
A
A
Dipartimento di Scienze Biochimiche e Centro di Biologia Molecolare del C.N.R., Universita di Roma La Sapienza, Italy.
Ippoliti
R
R
Brunori
M
M
Kam
Z
Z
Benveniste
M
M
Emmanuel
F
F
Turpin
E
E
Alfsen
A
A
Frénoy
J P
JP
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
D005452:Fluoresceins; D005456:Fluorescent Dyes; D046911:Macromolecular Substances; D013861:Thiocyanates; D012276:Ricin; D016650:Fluorescein-5-isothiocyanate