Synthesis and biological evaluation of an iodinated iberiotoxin analogue, [mono-iodo-Tyr5, Phe36]-iberiotoxin

E S Kozlowski1, G Johnson, D D Dischino

  • 1Department of Central Nervous System Chemistry, Richard L. Gelb Center for Pharmaceutical Research and Development, Bristol-Myers Squibb, Wallingford, Connecticut, USA.

International Journal of Peptide and Protein Research
|August 1, 1996
PubMed

The synthesis and iodination of a structural analogue of the specific large-conductance calcium-activated potassium (BK) channel blocker, iberiotoxin (IbTX), a 37-amino acid scorpion neurotoxin, is reported. The synthesis of this analogue, [Tyr5, Phe36]-IbTX, was accomplished using standard solid-phase Fmoc (9-fluorenylmethoxycarbonyl) chemistry protocols. The linear peptide was cyclized via the formation of three intramolecular disulfide bridges and subsequently iodinated at the Tyr5 position. Upon purification, the iodinated analogue, [mono-iodo-Tyr5, Phe36]-IbTX, exhibited comparable biological activity to native IbTX in blocking BK-mediated currents. These findings suggest the synthesis and use of an 125I labelled IbTX analogue for BK channel localization in autoradiography experiments.

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