Crowding revisited: Open questions and future perspectives. Issue 12 (December 2022)

• Record Type: Journal Article
• Authors: Pastore, Annalisa; Temussi, Piero Andrea
• Is Part Of: Trends in biochemical sciences. Volume 47:Issue 12(2022)
• Page Start: 1048
• Page End: 1058
• Publication Date: 2022-12
• Subjects: molecular crowding -- protein stability -- thermodynamics; Biochemistry -- Periodicals; 572
• DOI: 10.1016/j.tibs.2022.05.007
• Languages: English
• ISSNs: 0968-0004

Abstract

Abstract : Although biophysical studies have traditionally been performed in diluted solutions, it was pointed out in the late 1990s that the cellular milieu contains several other macromolecules, creating a condition of molecular crowding. How crowding affects protein stability is an important question heatedly discussed over the past 20 years. Theoretical estimations have suggested a 5–20°C effect of fold stabilisation. This estimate, however, is at variance with what has been verified experimentally that proposes only a limited increase of stability, opening the question whether some of the assumptions taken for granted should be reconsidered. The present review critically analyses the causes of this discrepancy and discusses the limitations and implications of the current concept of crowding. Highlights: The interior of cells is an aqueous solution much more concentrated than buffers used for in vitro studies, posing the problem of how such 'crowded' conditions influence protein stability and other properties. The presence of high concentrations of crowders limits the volume available to proteins under study and impacts their thermal stability. The influence of crowders on protein stability is modulated by the presence of enthalpic contributions, which may shield the real mechanism of crowding. Careful studies that minimise weak interactions support the importance of entropic contributions.