Method for radiolabeling monovalent antibody fragments
AssigneeImmunomedics, Inc.
InventorsChien-Hsing Chang, Anastasia L. Jones
Life of this patent
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Abstract
A method for radiolabeling a monovalent Fab or Fab' antibody fragment which comprises the steps of cleaving a divalent F(ab).sub.2 or F(ab').sub.2 antibody fragment using sulfite or meta-bisulfite ions to produce a monovalent fragment having a free sulfhydryl group, and contacting the monovalent fragment with a cation of a metallic radionuclide which binds to sulfhydryl groups, without removing excess sulfite or metabisulfite.
Claims22
A method for producing a radionuclide-labeled monovalent antibody fragment which comprises the steps of:
- (a) cleaving a divalent F(ab).sub.2 or F(ab').sub.2 antibody fragment using sulfite or meta-bisulfite ions to produce monovalent Fab or Fab' antibody fragments having free sulfhydryl and S-sulfonate groups;
- (b) contacting said monovalent Fab or Fab' antibody fragments with a sufficient amount of stannous ions to reduce said S-sulfonate groups to free sulfhydryl groups and to reduce radiopertechnetate or radioperrhenate ions added subsequently;
- and
- (c) contacting said monovalent Fab or Fab' antibody fragments having free sulfhydryl groups with radiopertechnetate or radioperrhenate ions, without removing excess sulfite or meta-bisulfite ions, to produce radionuclide-labeled monovalent Fab or Fab' antibody fragments having reduced radiopertechnetate or radioperrhenate ions bound to said sulfhydryl groups.
A method for producing a radionuclide-labeled protein which comprises the steps of:
- (a) cleaving disulfide bonds in a protein containing disulfide bonds using sulfite or meta-bisulfite ions to produce an intermediate protein having free sulfhydryl and S-sulfonate groups;
- (b) contacting said intermediate protein with an amount of stannous ions sufficient to reduce said S-sulfonate groups to free sulfhydryl groups and to reduce radiopertechnetate or radioperrhenate ions added subsequently;
- and
- (c) contacting said intermediate protein having free sulfhydryl groups with radiopertechnetate or radioperrhenate ions, without removing excess sulfite or meta-bisulfite ions, to produce a radionuclide-labeled protein having reduced radiopertechnetate or radioperrhenate ions bound to said sulfhydryl groups.
Dependencies are inferred from the claim text.