Thermodynamics of unfolding of the all beta-sheet protein interleukin-1 beta.


The thermal denaturation of interleukin-1 beta in solution has been studied by differential scanning calorimetry at various pH values. It is shown that the thermal transition of interleukin-1 beta is completely reversible below pH 2.5, only partly reversible in the pH range 2.5-3.5, and irreversible above pH 3.5. Analysis of the reversible unfolding of interleukin-1 beta shows that the heat denaturation is well approximated by a two-state transition and is accompanied by a significant increase of heat capacity. The partial heat capacity of denatured interleukin-1 beta is very close to that expected for the completely unfolded protein. This permitted us to assign the thermodynamic characteristics of interleukin-1 beta denaturation to its complete unfolding and to correlate them with structural features of the protein. The contributions of hydrogen bonding and hydrophobic interactions to the stability of interleukin-1 beta are analyzed and compared to those for other globular proteins. It is shown that the Gibbs energy of a hydrogen bond in a beta-sheet structure is greater than in alpha-helices. Study holds ProTherm entries: 4510, 4511, 4512, 4513, 4514 Extra Details:

Submission Details


Submitter: Connie Wang

Submission Date: April 24, 2018, 8:25 p.m.

Version: 1

Publication Details
Makhatadze GI;Clore GM;Gronenborn AM;Privalov PL,Biochemistry (1994) Thermodynamics of unfolding of the all beta-sheet protein interleukin-1 beta. PMID:8049234
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