Electron-Gated Ion Channels : With Amplification by NH3 Inversion Resonance

With more than 100 billion (10^11) neurons in our nervous system, each having thousands of ion channels, nature would likely have evolved a simple, robust, low-energy gating system to control the flow of ions into and out of the cell. Such a system, based on electron tunneling and quantum mechanics, is the subject of this book documenting the author’s research on electron gating. Electron tunneling in proteins is a much-studied phenomenon; however, for electrons to control ion channel gates, a mechanism for amplification is required. During the research, it was discovered that NH3 groups at the end of arginine and lysine side chains are inverting and increasing the sensitivity of electron transfer to changes in the electric field. The inversion frequency for NH3, on the arginine side chain, was determined experimentally in Blue Fluorescent Protein using a new microwave spectroscopy technique developed for this purpose. The inversion frequency of NH3 in the gas phase occurs at about 24 GHz and is used for amplification in the ammonia maser. This frequency, reduced by the attachment of NH3 to the side chain, is the basis for amplification at arginine and lysine sites. The amplification led to development of electron gating models for sodium and potassium ion channels and to a model for calcium oscillators. The electron gating models match and explain, for the first time, the complex rate curves, described by the classic (1952) Hodgkin-Huxley equations. Amplified electron tunneling and gating opens the door to understanding nature’s mechanisms for timing, memory, and calcium signaling.