Antigen-binding site protection during radiolabeling leads to a higher immunoreactive fraction

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Journal of Nuclear Medicine; (USA)

OSTI ID:5895690

Van den Abbeele, A D; Aaronson, R A; Daher, S; Taube, R A; Adelstein, S J; Kassis, A I ^[1]

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1. Harvard Medical School, Boston, MA (USA)

It is generally accepted that the immunointegrity of an antibody (Ab) depends on the preservation of its antigen-binding sites. Our goal was to radiolabel an antibody at several iodine:antibody molar ratios under conditions protecting its combining site and to compare its immunoreactive fraction (IRF) and electrophoretic mobility with those of the same antibody radiolabeled without protection. The data indicate that an antibody radiolabeled while its antigen-binding site is occupied by its antigen had the same IRF, regardless of the number of iodine atoms per antibody molecule. On the other hand, even at an I:Ab ratio of 1:1, the IRF of the same antibody radiolabeled without protection was lower than that of a protected one and decreased with increasing I:Ab ratios. In addition, the iodination of these Ab changes their electrophoretic mobility; however, when the Ab is labeled in the protected state, the degree of change is less. The binding of an antibody to its antigen prior to radiolabeling, therefore, enhances its immuno-integrity and prevents major conformational changes as reflected by electrophoresis.

• OSTI ID: 5895690
• Journal Information: Journal of Nuclear Medicine; (USA), Vol. 32:1; ISSN 0161-5505
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANTIGENS
RECEPTORS
MONOCLONAL ANTIBODIES
LABELLING
ANTIGEN-ANTIBODY REACTIONS
ELECTROPHORESIS
GOATS
IMMUNE REACTIONS
IODINE ISOTOPES
RABBITS
TRACER TECHNIQUES
ANIMALS
ANTIBODIES
DOMESTIC ANIMALS
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEMBRANE PROTEINS
ORGANIC COMPOUNDS
PROTEINS
RUMINANTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques