Anaesthetics & consciousness 2
Halothane binding proteome in human brain cortex :: Roderic Eckenhoff, Maryellen Eckenhoff et al, University of Pennsylvania :: Journal of Proteome Research, 2007, 6, pp. 582-592 :: http://pubs.acs.org/doi/pdf/10.1021/pr060311u
Summary and review of the above paper
This later study demonstrated that anaesthetics could interact with many human brain proteins; previous studies has been confined to rodent brains. Recent research has expanded rather than contracted the potential targets for anaesthetic gases. Anaesthetic molecules are known to bind to numerous different proteins in the brain. Some at least of these proteins must be involved with anaesthesia.
In a study using halothane, 23 membrane proteins and 34 soluble proteins were identified. It thus appears possible that the large category of soluble proteins could be involved in anaesthesia. The involvement of soluble proteins as distinct from membrane proteins does not conflict with Overton-Meyer, since the interiors of soluble proteins are as hydrophobic as membrane proteins.
Mitochondria and anaesthesia
Ion channels, synaptic vesicle trafficking proteins and mitochondrial complexes are all viewed as potential sites for the action of anaesthesia. Previous studies pointed to mitochondrial targets including parts of the respiratory complex and ATP synthase. In some cases, interactions between membrane and soluble proteins were a factor. When these interacting proteins were included the list of 34 soluble proteins could be extend to a total of 44 proteins. Some of the overlapping proteins are mitochondrial proteins. Three of the identified proteins are located on the mitochondrial membrane and this is consistent with the effect of anaesthesia on cellular mechanism. The mitochondrion is viewed as a potential anaesthetic target. Studies have suggested that enzymes related to the mitochondria or targets in the mitochondrial potassium channel could play a role in the effect of anaesthetics.