Table 1.
Non-Cholinesterase Targets of OPs (at physiologically relevant concentrations)
| Target | Description/Functions | Reference (s) |
|---|---|---|
| papain | cysteine protease found in lysozomes | Chaiken and Smith, 1969 |
| carboxylesterase | Serine hydrolase/enzyme that hydrolyzes carboxyl esters | Su et al., 1971; Chanda et al., 1997 |
| adenylyl cyclase | Enzyme that catalyzes the conversion of ATP to cyclic AMP/Important in the G protein signaling cascade | Huff et al., 1994; Song et al., 1997; Auman et al., 2000 |
| Neuropathy target esterase | Phospholipase enzyme important in phospholipid metabolism, neurite outgrowth and process elongation during neuronal differentiation | Lush et al., 1998 |
| acylpeptide hydrolase | Serine protease enzyme that catalyzes the removal of N- acylated amino acids from acetylated peptides role in the coordinated protein-degradation | Richards et al., 2000 |
| M2 muscarinic receptors | Second messenger coupled acetylcholine autoreceptor | Bomser and Casida 2001* |
| fatty acid amide hydrolase | Serine hydrolase enzyme that catabolizes a class of bioactive lipids called the fatty acid amides including endocannabinoids (e.g., anandamide) | Quistad et al., 2001 |
| cannabinoid CB1 receptors | G protein-coupled receptors for endocannabinoids/functions not fully understood, but may play roles in neurotransmitter release, synaptic plasticity, pleasure, appetite, memory/concentration, perception of time, pain tolerance, etc. | Quistad et al., 2002 |
| albumin | Most abundant transport protein in plasma, also regulates the colloidal osmotic pressure of blood | Peeples et al., 2005 |
| transferrin | Glycoprotein that binds and transports iron in the plasma | Grigoryan et al., 2009 |
| kinesin | Motor protein involved in anterograde axonal transport in neurons as well as other cellular functions such as mitosis, meiosis, etc. | Grigoryan et al., 2009 |
| ATP Synthase | Mitochondrial enzyme responsible for synthesizing ATP from ADP and inorganic phosphate | Grigoryan et al., 2009 |
| tubulin | Globular proteins that form microtubules (i.e., polymers of dimerized tubulin which serve structural roles in the cytoskeleton, support intracellular transport, mitosis, etc.) | Jiang et al., 2010 |
*
OP-phosphorylation of M2 receptors reported by Bomser and Casida 2001 (using chlorpyrifos oxon) was not observed in experiments where paraoxon or a biotinlabeled fluorophosphonate were evaluated (Proskocil et al., 2010).