Protein stability: the value of 'old literature'.

The concepts of protein structure and function have been subjects of intensive study throughout the 20th century; they continue to fascinate present-day scientists. Our understanding received a major boost when it was realised during the 1960s, that the physical properties of water play a major role in determining the stability of native proteins in vitro. This recognition changed the emphasis of physicochemical studies towards 'hydration', i.e. protein-water interactions. A rigorous quantitative description of 'hydration' still escapes us, but several semi-quantitative treatments, some with predictive potential, are now available and can account for the marginal stabilities of native proteins in aqueous solvent environments. This article charts the progress achieved during the latter half of the 20th century, which in present day parlance is termed 'old literature'. The thesis is advanced that the common practice of uncritically equating 'recent literature' with 'progress' is of dubious value. In the general area of in vitro protein stability some recent developments seem questionable and have yet to stand the test of time before their usefulness or validity can be accepted.