Lowering of pI by acylation improves the renal uptake of 99mTc-labeled anti-Tac dsFv: Effect of different acylating reagents

Insook Kim, Hisataka Kobayashi, Tae M. Yoo, Meyong kon Kim, Nhat Le, Eui sik Han, Q. C. Wang, Ira Pastan, Jorge A. Carrasquillo, Chang H. Paik

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13 Citations (Scopus)

Abstract

Anti-Tac disulfide-stabilized variable region fragment (dsFv) was labeled with 99mTc by a preformed chelate approach using 99mTc-MAG3-trifluorophenyl (TFP) ester. Simultaneously it was acylated with TFP-lactate or succinic anhydride to decrease the isoelectric point of dsFv (pI 10). Acylation of dsFv (0.04 mM) with the lactate at a 73 times molar excess reduced the pI to 5.0-6.7, whereas acylation with succinic anhydride at a 30 times molar excess reduced the pI to 4.9-8.7. Comparative biodistribution studies performed in mice (n = 5) showed the reduced renal accumulation of the 99mTc proportional to the pI reduction. The effect of the pI on the reduced renal uptake was especially pronounced at 15 min postinjection. The reduced renal uptake was also reflected in the reduced whole-body retention, indicating that lowering the pI inhibited the tubular reabsorption of the labeled dsFv.

Original languageEnglish
Pages (from-to)795-801
Number of pages7
JournalNuclear Medicine and Biology
Volume29
Issue number8
DOIs
Publication statusPublished - 2002 Nov 1

Keywords

  • Enhanced renal clearance
  • Isoelectric point
  • Tc-MAG3-dsFv

ASJC Scopus subject areas

  • Molecular Medicine
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

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    Kim, I., Kobayashi, H., Yoo, T. M., Kim, M. K., Le, N., Han, E. S., Wang, Q. C., Pastan, I., Carrasquillo, J. A., & Paik, C. H. (2002). Lowering of pI by acylation improves the renal uptake of 99mTc-labeled anti-Tac dsFv: Effect of different acylating reagents. Nuclear Medicine and Biology, 29(8), 795-801. https://doi.org/10.1016/S0969-8051(02)00341-4