Activation energy of the dynein motor protein in dorsal root ganglia

Value 22.5 kcal/mol Range: ±0.6 kcal/mol
Organism Rat Rattus norvegicus
Reference Kai Zhang et al., Single-molecule imaging of NGF axonal transport in microfluidic devices. Lab Chip. 2010 Oct 7 10(19):2566-73. doi: 10.1039/c003385e. p.6 top paragraphPubMed ID20623041
Method Abstract: "Here, [investigators] employed a microfluidic culture platform to achieve background reduction for single molecule imaging in live neurons. Microfluidic devices guide the growth of neurons and allow separately-controlled microenvironment for cell bodies or axon termini. Designs of microfluidic devices were optimized and a three-compartment device successfully achieved direct observation of axonal transport of single NGF when quantum dot labeled NGF (Qdot-NGF) was applied only to the distal-axon compartment while imaging was carried out exclusively in the cell-body compartment."
Comments P.5 bottom paragraph: "[Investigators'] measurements favor an exponential rather than a linear relation between the transport rate and the temperature (Fig. 5C). The temperature dependence of the rate for NGF [Nerve growth factor] transport is also presented in the form of an Arrhenius plot in the insert of Fig. 5C. Over this range of temperatures, 14–36°C, a linear relationship between the natural logarithm of velocity versus the reciprocal of absolute temperature was obtained. The Q10 was approximately 3.0, and the Arrhenius activation energy calculated from the slope was 22.5 ± 0.6 kcal/mol. This value falls in the range of reported activation energy 15–26 kcal/mol for molecular motors, but is somewhat higher than the previously reported activation energy for dynein motors using radio-labeled protein assay (~15 kcal/mol)."
Entered by Uri M
ID 114858