Abstract

The present paper attempts to demonstrate semiotic arguments against the sequence → structure → function paradigm in protein studies. The unidirectional deterministic thinking in biological processes has been challenged by several disciplines of life sciences and philosophy. Biosemiotics comprehends living organisms as actively participating in their present and somehow creating or shaping their future, having a plurality of options for acting. Determinism and unidirectionality are in contradiction with a biosemiotic approach towards life, mostly when considering Peirce’s triadic concept of semiosis. In this paper, a Peircean biosemiotic approach is applied to proteins and to the process of protein folding. Two main concepts are presented to support the arguments against the SSF paradigm in protein studies: the NonReduction Theorem and the notion of folded continuum. A processual approach is proposed as the most suitable for descriptions of proteins and their functions.