BM42017/10.26125/dw2b-m249

Wisdom of the crowd

Author(s): Liel Sapir and Daniel Harries

Publication: Bunsenmagazin, Issue 4 2017, Aspekte, Seiten: 152 - 162

Publisher: Deutsche Bunsen-Gesellschaft für physikalische Chemie e.V., Frankfurt

Language: English

DOI: 10.26125/dw2b-m249

 

Introduction

On a hot summer’s day you decide to cool off in the neighborhood swimming pool. The pool is jam-packed with others trying to do the same, but you venture to go in, anyway. The stress and crowded feeling is (more or less) what a macromolecule would feel inside a living cell. The third or so dry mass of an average cell translates in the pool analogy to you easily being able to hold hands with your nearest neighbors. Some four decades ago it was realized that this kind of environment must have implications to the way cellular macromolecules interact. To get from one side of the pool to the other, for example, would require a collective movement of you and your neighbors to allow passage. The mere excluded volume of your neighbors (and some people in the pool seem to have much more of that than others) makes it difficult to find specific partners by simple diffusion. But crowding may have its pros, too. By driving macromolecules such as proteins towards the more compact state, even sterio interacrions alone may suffice to stabilize their structure. Additional effective forces between neighboring molecules in solution (that can be repulsive or attractive by nature) further modulate, or even dominate, this stabilization. Importantly, effective forces in solution can be exerted not only by large macromolecules, but also by molecularly small solutes (perhaps sardines were added to the pool?), but their action often shows distinct differences from larger crowders in the temperature dependence of crowding. Can we devise a common language to describe the rich variety of possible solvation effects on macromolecules in simple yet thermodynamically descriptive terms? We review the thermodynamic implications of solvation in dense solutions, comment on the importance of molecular interactions beyond excluded volume to this effect, and outline the implications for small versus large solutes. Finally, we discuss how the interactions between all components in a dense milieu modulate the temperature response of macromolecular stability.

 

Cite this: Liel Sapir, Daniel Harries (2017): Wisdom of the crowd. Bunsenmagazin 2017, 4: 152-162. Frankfurt am Main: Deutsche Bunsen-Gesellschaft für physikalische Chemie e.V. DOI: 10.26125/dw2b-m249

 

 

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