UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-23 18:02

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Conference: Bucharest University Faculty of Physics 2019 Meeting


Section: Biophysics; Medical Physics


Title:
Biophysics of protein folding: mechanism and importance


Authors:
Claudia G. CHILOM, Marcela E. BĂRBÎNȚĂ-PĂTRAȘCU, Doina M. GĂZDARU, Aurel I. POPESCU


Affiliation:
Department of Electricity, Physics of Solid and Biophysics, Faculty of Physics,

University of Bucharest



E-mail
prof.aurel.popescu@gmail.com


Keywords:
Random coil protein, native protein state, folding mechanism, chaperones, protein folding diseases


Abstract:
A cell expresses over 10,000 proteins for: metabolism driving, morphology maintaining, and signal producing towards other cells. All these proteins are properly operating only if they possess a native space structure. This means that every member of a populations of a specific class of proteins is naturally adopting the same space configuration. Otherwise, any critical deviation from the specific native structure is implying significant alteration of protein function. Protein folding is the dynamical process by which a protein attains its functional 3D conformation. Two factors mainly contribute to protein folding: the properties of its amino acids and the influences of the crowded cellular microenvironment of the nascent protein. The small proteins are spontaneously folding, whereas the larger ones need to be assisted by other proteins, named chaperones, otherwise they risk to be incorrectly folded. Although the number of the intermediary states, starting from unfolded nascent states to the unique native state, is huge, the folding is very rapid (from microseconds to seconds), implying energetically favoured folding paths. Protein folding not only generates biologically active structures, but also protects the protein from degradation by proteases and reduces the probability of abnormal aggregation as in the case of some diseases (e.g., Alzheimer, Parkinson). The ability of proteins to fold rapidly is an evolutionary gain that favours them in competition with aggregations (i.e., amyloidal structures) by which these diseases are provoked.


References:

1. Raicu V. and Popescu A. (2008) Integrated Molecular and Cellular Biophysics, Edition Springer

2. Popescu A. (2016) Biophysics. Current Status and Future Trends. The Publishing House of the Romanian Academy