A Monist Proposal: Against Integrative Pluralism About Protein Structure

Abstract

Mitchell & Gronenborn (2017) propose that we account for the presence of multiple models of protein structure, each produced in different contexts, through the framework of integrative pluralism. I argue that two interpretations of this framework are available, neither of which captures the relationship between a model and the protein structure it represents or between multiple models of protein structure. Further, it inclines us toward concluding prematurely that models of protein structure are right in their contexts and makes extrapolation of findings from one context to another seem unwarranted. Instead, protein structure determination ought to be understood as modestly monistic. There is one model for every protein in each physicochemical context, and models of the same protein produced in different contexts are compatible with one another. 'Integrating' multiple models amounts to extrapolating from one context to another; this is possible because the effect of context on protein folding is relatively weak and predictable. Modest monism better describes the practice of protein structure determination than integrative pluralism and enables greater attention to how context affects protein folding.1 For instance, there might be 3 100 possible states for a polypeptide chain of just 100 amino acids, and this is on the conservative assumption that each amino acid can adopt only three conformations (Levinthal,