Labeling proteins using aryl iodide acylation agents: influence of meta vs para substitution on in vivo stability

Int J Rad Appl Instrum B. 1989;16(7):669-73. doi: 10.1016/0883-2897(89)90136-0.


The effect of para vs meta substitution on the biological behavior of an intact antibody and an F(ab')2 fragment was investigated. Paired-label studies were performed using 81C6 IgG and OC 125 F(ab')2 labeled using the N-succinimidyl esters of both p-[125I]- and m-[131I]iodobenzoate as well as with the potential catabolites, p-[125I]- and m-[131I]iodobenzoic acid. In all 3 studies, up to 55% lower uptake of 131I in thyroid and stomach was observed, suggesting that the m-substituted species were more inert to dehalogenation in vivo.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Monoclonal / pharmacokinetics
  • Drug Stability
  • Immunoglobulin Fab Fragments / immunology
  • Immunoglobulin Fab Fragments / pharmacokinetics
  • Iodine Radioisotopes
  • Iodobenzoates / chemical synthesis*
  • Iodobenzoates / pharmacokinetics
  • Isotope Labeling / methods*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Proteins / immunology
  • Tissue Distribution


  • Antibodies, Monoclonal
  • Immunoglobulin Fab Fragments
  • Iodine Radioisotopes
  • Iodobenzoates
  • Neoplasm Proteins
  • N-succinimidyl 4-iodobenzoate
  • N-succinimidyl 3-iodobenzoate