The histidine phosphocarrier kinase/phosphorylase from bacillus subtilis is an oligomer in solution with a high thermal stability

Neira, J.L. ; Cámara-Artigas, A. ; Hernández-Cifre, J.G. ; Ortore, M.G.

Resumen: The histidine phosphocarrier protein (HPr) kinase/phosphorylase (HPrK/P) modulates the phosphorylation state of the HPr protein, and it is involved in the use of carbon sources by Gram-positive bacteria. Its X-ray structure, as concluded from crystals of proteins from several species, is a hexamer; however, there are no studies about its conformational stability, and how its structure is modified by the pH. We have embarked on the conformational characterization of HPrK/P of Bacillus subtilis (bsHPrK/P) in solution by using several spectroscopic (namely, fluorescence and circular dichroism (CD)) and biophysical techniques (namely, small-angle X-ray-scattering (SAXS) and dynamic light-scattering (DLS)). bsHPrK/P was mainly a hexamer in solution at pH 7.0, in the presence of phosphate. The protein had a high conformational stability, with an apparent thermal denaturation midpoint of ~70¿ C, at pH 7.0, as monitored by fluorescence and CD. The protein was very pH-sensitive, precipitated between pH 3.5 and 6.5; below pH 3.5, it had a molten-globule-like conformation; and it acquired a native-like structure in a narrow pH range (between pH 7.0 and 8.0). Guanidinium hydrochloride (GdmCl) denaturation occurred through an oligomeric intermediate. On the other hand, urea denaturation occurred as a single transition, in the range of concentrations between 1.8 and 18 µM, as detected by far-UV CD and fluorescence.

Idioma: Inglés

DOI: 10.3390/ijms22063231

Año: 2021

Publicado en: International Journal of Molecular Sciences 22, 6 (2021), 3231 [23 pp.]
ISSN: 1661-6596

Factor impacto JCR: 6.208 (2021)

Categ. JCR: BIOCHEMISTRY & MOLECULAR BIOLOGY rank: 69 / 297 = 0.232 (2021) - Q1 - T1
Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 50 / 180 = 0.278 (2021) - Q2 - T1

Factor impacto CITESCORE: 6.9 - Computer Science (Q1) - Chemical Engineering (Q1) - Medicine (Q1) - Biochemistry, Genetics and Molecular Biology (Q2)

Factor impacto SCIMAGO: 1.176 - Computer Science Applications (Q1) - Inorganic Chemistry (Q1) - Spectroscopy (Q1) - Organic Chemistry (Q1) - Physical and Theoretical Chemistry (Q1) - Molecular Biology (Q1)

Financiación: info:eu-repo/grantAgreement/ES/AEI/CTQ2017-85425-P
Financiación: info:eu-repo/grantAgreement/ES/MCIU-AEI-FEDER/RTI2018-097991-B-I00
Financiación: info:eu-repo/grantAgreement/ES/MINECO/BIO2016-78020-R

Tipo y forma: Article (Published version)