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Chaperone-Like Activity of HSPB5: The Effects of Quaternary Structure Dynamics and Crowding

Authors :
Tatiana B. Eronina
Valeriya V. Mikhaylova
Boris I. Kurganov
Natalia A. Chebotareva
Svetlana G. Roman
Vera A. Borzova
Source :
International Journal of Molecular Sciences, Volume 21, Issue 14, International Journal of Molecular Sciences, Vol 21, Iss 4940, p 4940 (2020)
Publication Year :
2020
Publisher :
Multidisciplinary Digital Publishing Institute, 2020.

Abstract

Small heat-shock proteins (sHSPs) are ATP-independent molecular chaperones that interact with partially unfolded proteins, preventing their aberrant aggregation, thereby exhibiting a chaperone-like activity. Dynamics of the quaternary structure plays an important role in the chaperone-like activity of sHSPs. However, relationship between the dynamic structure of sHSPs and their chaperone-like activity remains insufficiently characterized. Many factors (temperature, ions, a target protein, crowding etc.) affect the structure and activity of sHSPs. The least studied is an effect of crowding on sHSPs activity. In this work the chaperone-like activity of HSPB5 was quantitatively characterized by dynamic light scattering using two test systems, namely test systems based on heat-induced aggregation of muscle glycogen phosphorylase b (Phb) at 48 &deg<br />C and dithiothreitol-induced aggregation of &alpha<br />lactalbumin at 37 &deg<br />C. Analytical ultracentrifugation was used to control the oligomeric state of HSPB5 and target proteins. The possible anti-aggregation functioning of suboligomeric forms of HSPB5 is discussed. The effect of crowding on HSPB5 anti-aggregation activity was characterized using Phb as a target protein. The duration of the nucleation stage was shown to decrease with simultaneous increase in the relative rate of aggregation of Phb in the presence of HSPB5 under crowded conditions. Crowding may subtly modulate sHSPs activity.

Details

Language :
English
ISSN :
14220067
Database :
OpenAIRE
Journal :
International Journal of Molecular Sciences
Accession number :
edsair.doi.dedup.....66382acc356b3077037f0a3443414a3e
Full Text :
https://doi.org/10.3390/ijms21144940