The finite size effects and two-state paradigm of protein folding
The coil to globule transition of the polypeptide chain is the physical phenomenon behind the folding of globular proteins. Globular proteins with a single domain usually consist of about 30 to 100 amino acid residues, and this finite size extends the transition interval of the coil-globule phase transition. Based on the pedantic derivation of the two-state model, we introduce the number of amino acid residues of a polypeptide chain as a parameter in the expressions for two cooperativity measures and reveal their physical significance. We conclude that the k2 measure, defined as the ratio of van ’t Hoff and calorimetric enthalpy is related to the degeneracy of the denatured state and describes the number of cooperative units involved in the transition; additionally, it is found that the widely discussed k2=1 is just the necessary condition to classify the protein as the two-state folder. We also find that Ωc, a quantity not limited from above and growing with system size, is simply proportional to the square of the transition interval. This fact allows us to perform the classical size scaling analysis of the coil-globule phase transition. Moreover, these two measures are shown to describe different characteristics of protein folding
2021
2021-02-24 17:21:46
1033
protein folding, two-state model, size scaling, thermodynamic cooperativity
Artem
Badasyan
70
Matjaž
Valant
70
Jože
Grdadolnik
70
Vladimir N.
Uversky
70
COBISS_ID
3
53005059
UDK
4
577
ISSN pri članku
9
1422-0067
URN
14
URN:SI:UNG:REP:XCU3LRVU
DOI
15
10.3390/ijms22042184
0
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2021-02-24 20:23:35
Badasyan2021ijms-22-02184.pdf
269518
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2021-02-24 17:22:19
0
Izvorni URL
2021-02-24 17:21:57