Neonicotinoids binding assay

Neonicotinoids do not act as a homogenous class of insecticides. Radioligand receptor binding assays revealed two classes of neonicotinoids described here as competitive and non-competitive , respectively, relative to [ H]imidacloprid. Differences in affinity, mode of displacement, number of binding sites and temperature sensitivity suggest that thiamethoxam binds in a way unique among the commercial neonicotinoids. Metabolic transformation is not relevant for its insecticidal effects. 

As effects like those documented for thiamethoxam have not yet been described in the receptor binding field, the results, though based on thorough and self-critical experimentation, may be questioned. In our view, these novel results necessarily call for novel interpretations. A most evident conclusion from the present results is that binding of thiamethoxam has a different impact (as measurable in binding assays) on the receptor complex as binding of other, competitive neonicotinoids. Whether this different mode of interaction is due... 

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