Concentration-Dependent Structural Transition of the HIV-1 gp41 MPER Peptide into α-Helical Trimers.

ABSTRACT: The membrane proximal external region (MPER) of HIV-1 gp41 contains epitopes for at least four broadly neutralizing antibodies. Depending on solution conditions and construct design, different structures have been reported for this segment. We show that in aqueous solution the MPER fragment (gp160^660-674 ) exists in a monomer-trimer equilibrium with an association constant in the micromolar range. Thermodynamic analysis reveals that the association is exothermic, more favorable in D₂ O than H₂ O, and increases with ionic strength, indicating hydrophobically driven intermolecular interactions. Circular dichroism, ¹³ C^α chemical shifts, NOE, and hydrogen exchange rates reveal that MPER undergoes a structural transition from predominately

SUBMITTER: Chiliveri SC 

PROVIDER: S-EPMC7755662 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature