Physical limits on computation by assemblies of allosteric proteins
Abstract
Assemblies of allosteric proteins, nano-scale Brownian computers, are the principle information processing devices in biology. The troponin C-troponin I (TnC-TnI) complex, the Ca-sensitive regulatory switch of the heart, is a paradigm for Brownian computation. TnC and TnI specialize in sensing (reading) and reporting (writing) tasks of computation. We have examined this complex using a newly developed phenomenological model of allostery. Nearest-neighbor-limited interactions among members of the assembly place previously unrecognized constrains the topology of the system's free energy landscape and generate degenerate transition probabilities. As a result, signaling fidelity and deactivation kinetics can not be simultaneously optimized. This trade-off places an upper limit on the rate of information processing by assemblies of allosteric proteins that couple to a single ligand chemical bath.
Cite
@article{arxiv.0802.1034,
title = {Physical limits on computation by assemblies of allosteric proteins},
author = {John M. Robinson},
journal= {arXiv preprint arXiv:0802.1034},
year = {2009}
}
Comments
6 pages, 3 figures. 2 pages of supplemental information