title: Metabolic Free Energy and Biological Codes: A 'Data Rate Theorem' Aging Model.
abstract: A famous argument by Maturana and Varela (Autopoiesis and cognition. Reidel, Dordrecht, 1980) holds that the living state is cognitive at every scale and level of organization. Since it is possible to associate many cognitive processes with 'dual' information sources, pathologies can sometimes be addressed using statistical models based on the Shannon Coding, the Shannon-McMillan Source Coding, the Rate Distortion, and the Data Rate Theorems, which impose necessary conditions on information transmission and system control. Deterministic-but-for-error biological codes do not directly invoke cognition, but may be essential subcomponents within larger cognitive processes. A formal argument, however, places such codes within a similar framework, with metabolic free energy serving as a 'control signal' stabilizing biochemical code-and-translator dynamics in the presence of noise. Demand beyond available energy supply triggers punctuated destabilization of the coding channel, affecting essential biological functions. Aging, normal or prematurely driven by psychosocial or environmental stressors, must interfere with the routine operation of such mechanisms, initiating the chronic diseases associated with senescence. Amyloid fibril formation, intrinsically disordered protein logic gates, and cell surface glycan/lectin 'kelp bed' logic gates are reviewed from this perspective. The results generalize beyond coding machineries having easily recognizable symmetry modes, and strip a layer of mathematical complication from the study of phase transitions in nonequilibrium biological systems.
authors.affiliation: Division of Epidemiology, New York State Psychiatric Institute, New York, NY, USA, Wallace@nyspi.columbia.edu.
authors.forename: Rodrick
authors.initials: R
authors.lastname: Wallace
mesh_terms: D000375:Aging / Q000378:metabolism*; D000682:Amyloid / Q000096:biosynthesis; D000818:Animals; D004734:Energy Metabolism; D006801:Humans; D064267:Intrinsically Disordered Proteins / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D055641:Mathematical Concepts; D008954:Models, Biological; D011134:Polysaccharides / Q000378:metabolism; D013598:Systems Theory
chemical_list: D000682:Amyloid; D064267:Intrinsically Disordered Proteins; D037102:Lectins; D011134:Polysaccharides