Plakhova V B, Shchegolev B F, Rogachevskii I V, Nozdrachev A D, Krylov B V, Podzorova S A, Kokryakov V N
I. P. Pavlov Institute of Physiology, St. Petersburg, Russia.
Neurosci Behav Physiol. 2002 Jul-Aug;32(4):409-15. doi: 10.1023/a:1015884312094.
A local membrane potential clamping method was used to study the effects of defensin NP-1 on the membranes of rat spinal ganglion neurons. NP-1 led to decreases in the effective charge for the activation gating system. This process depended on the NP-1 concentration. Use of the Hill equation showed that Kd was 2.10(-12) M and the Hill coefficient was 0.9. The structure of the defensin molecule was optimized using quantum chemical calculations based on a molecular mechanics method. The results obtained from these calculations suggested that a single hydroxyl group directed towards the outer part of thedefensin molecule and forming the carboxyl group of amino acid Glu14 could form a hydrogen bond with the active center of the membrane receptor. This explains the experimentally observed 1:1 stoichiometry of the ligand-receptor binding interaction between the defensin and the sensory neuron membrane.
