2023/11/17 by Sunita Kumari, Rudolf Podgornik, Kumari, Sunita +1 · 1 citation
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Biological Physics (physics.bio-ph) #FOS: Physical sciences #Lipid Membrane Structure and Behavior #Protein Structure and Dynamics
paper · pdf · doi:10.48550/arxiv.2311.10602
openalex publication_date 2023/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a derivation of the screening length for a solution containing a charge regulated macroion, e.g. protein, with its counterions. We show that it can be obtained directly from the second derivatives of the total free energy by taking recourse to the ``uncertainty relation" of the Legendre transform which connects the Hessians or the local curvatures of the free energy as a function of density and its Legendre transform, i.e., osmotic pressure, as a function of chemical potentials. Based on the Fowler-Guggenheim-Frumkin model of charge regulation we then analyze the ``screening resonance" and the ``overscreening" of the screening properties of the charge-regulated macroion solution.