Radioiodination of a monoclonal antibody using N-succinimidyl 5-iodo-3-pyridinecarboxylate.

Abstract

The potential utility of N-succinimidyl 5-iodo-3-pyridinecarboxylate (SIPC) for the radioiodination of monoclonal antibodies was investigated. Paired-label studies were performed using the anti-tenascin antibody 81C6 in athymic mice bearing subcutaneous D-54 MG human glioma xenografts. Radiolabeling was also done using N-succinimidyl 3-iodobenzoate (SIB). Radioiodination of SIPC and SIB both proceeded in 60-80% yield, but protein coupling efficiencies with SIB were higher (76 +/- 16 vs 60 +/- 7%). Immunoreactivity and affinity of both preparations were similar. Using SIPC, thyroid uptake was quite low, decreasing from 0.3% at day 1 to 0.05% at day 8. Tumor uptake reached 46 +/- 11% injected dose/g at day 1 but declined gradually thereafter. This apparent decline reflected the rapid growth of these xenografts since tumor accumulation expressed as percentage of injected dose remained nearly constant up to day 9. These results suggest that SIPC, like SIB, offers significant advantages for labeling antibodies when compared with conventional protein iodination methods.

• Authors: S Garg, P K Garg, X G Zhao, H S Friedman, D D Bigner, M R Zalutsky
• Journal: Nuclear medicine and biology (Nucl Med Biol) Vol. 20 Issue 7 Pg. 835-42 (Oct 1993) ISSN: 0969-8051 [Print] United States
• PMID: 8241995 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antibodies, Monoclonal
• Iodine Radioisotopes
• Nicotinic Acids
• Succinimides
• N-succinimidyl-5-iodo-3-pyridinecarboxylic acid

Topics

• Animals
• Antibodies, Monoclonal (metabolism)
• Glioma (metabolism)
• Iodine Radioisotopes (therapeutic use)
• Isotope Labeling (methods)
• Male
• Mice
• Mice, Inbred BALB C
• Neoplasm Transplantation
• Nicotinic Acids
• Succinimides
• Tissue Distribution
• Transplantation, Heterologous