How do HYNIC-conjugated peptides bind technetium? Insights from LC-MS and stability studies

King, R.C. and Surfraz, M.B. and Biagini, S.C.G. and Blower, P.J. and Mather, S.J. (2007) How do HYNIC-conjugated peptides bind technetium? Insights from LC-MS and stability studies. Dalton Transactions (43). pp. 4998-5007. ISSN 1477-9226 . (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1039/b705111e

Abstract

Hydrazinonicotinamide (HYNIC) is an established bifunctional complexing agent for technetium-99m ((99m)Tc) but the structure of the technetium coordination sphere remains uncertain. To gain further insight into this, we have prepared conjugates of HYNIC and hydrazinobenzoic acid (HYBA) with a model peptide, and radiolabelled them with (99m)Tc using three well-established co-ligand systems: EDDA, tricine and tricine-nicotinic acid. The labelled peptides were studied by LC-MS and by subjecting them to serum stability and protein binding assays. For each co-ligand system, HYNIC conjugates formed fewer and more stable labelled species than the corresponding HYBA conjugates. LC-MS analysis showed that all conjugates contained one hydrazine moiety bound to Tc, that binding of Tc to HYNIC-peptide and co-ligand occurs with displacement of 5H(+) indicating a Tc formal oxidation state of +5, and that the Tc has no oxo- or halide ligands. LC-MS also shows that complexes formed with the HYNIC conjugate contain fewer coordinating co-ligand molecules than the HYBA conjugate indicating that HYNIC is able to more effectively satisfy the coordination requirement of technetium, perhaps by binding in chelating mode.

Item Type: Article
Additional information: 1477-9226 (Print)Journal Article Research Support, Non-U.S. Gov't
Uncontrolled keywords: Chromatography, High Pressure Liquid/*methods Mass Spectrometry/*methods Peptides/*chemistry Technetium/*chemistry
Subjects: Q Science
Q Science > QD Chemistry
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Faculties > Science Technology and Medical Studies > School of Physical Sciences > Functional Materials Group
Faculties > Science Technology and Medical Studies > School of Physical Sciences
Depositing User: Sue Davies
Date Deposited: 07 Jul 2008 14:25
Last Modified: 21 May 2011 00:12
Resource URI: http://kar.kent.ac.uk/id/eprint/8030 (The current URI for this page, for reference purposes)
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