TY - JOUR
T1 - Structural mechanism of the Tanford transition of bovine β-lactoglobulin through microsecond molecular dynamics simulations
AU - Bello, Martiniano
N1 - Publisher Copyright:
© 2020 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2022
Y1 - 2022
N2 - X-ray analysis has provided structural data about a pH-driven conformational change in β-lactoglobulin (BLG) known as the Tanford transition, which occurs at around pH 7 and involves the EF loop, which acts as a lid closing the internal cavity of the protein below pH 7 and opening it above pH 7. NMR studies using wild-type BLG have encountered problems trying to explain the Tanford transition, however, they have provided important insight using a dimeric BLG mutant, revealing that the opening and closure of the EF loop consists of two types of motions in the microsecond and milliseconds timescales. This provides valuable information indicating that the dimeric state is a good model to study the Tanford transition, although the understanding of this structural change is still lacking at the atomic level. We performed microsecond molecular dynamics (MD) simulations starting from different conformations of BLG in the monomeric and dimeric state, with protonated and deprotonated E89, in order to explore the Tanford transition. Our results provide structural information for the transition from the closed to the open conformation in BLG and show it occurs in the dimeric state in the microsecond timescale, in line with the fast motion observed through NMR experiments. In addition, MD simulations coupled to MMGBSA approach indicated that the most populated conformer of BLG in the open state is able to bind ligands with similar affinity to that of BLG at neutral pH obtained through crystallographic experiments. Communicated by Ramaswamy H. Sarma.
AB - X-ray analysis has provided structural data about a pH-driven conformational change in β-lactoglobulin (BLG) known as the Tanford transition, which occurs at around pH 7 and involves the EF loop, which acts as a lid closing the internal cavity of the protein below pH 7 and opening it above pH 7. NMR studies using wild-type BLG have encountered problems trying to explain the Tanford transition, however, they have provided important insight using a dimeric BLG mutant, revealing that the opening and closure of the EF loop consists of two types of motions in the microsecond and milliseconds timescales. This provides valuable information indicating that the dimeric state is a good model to study the Tanford transition, although the understanding of this structural change is still lacking at the atomic level. We performed microsecond molecular dynamics (MD) simulations starting from different conformations of BLG in the monomeric and dimeric state, with protonated and deprotonated E89, in order to explore the Tanford transition. Our results provide structural information for the transition from the closed to the open conformation in BLG and show it occurs in the dimeric state in the microsecond timescale, in line with the fast motion observed through NMR experiments. In addition, MD simulations coupled to MMGBSA approach indicated that the most populated conformer of BLG in the open state is able to bind ligands with similar affinity to that of BLG at neutral pH obtained through crystallographic experiments. Communicated by Ramaswamy H. Sarma.
KW - Tanford transition
KW - binding free energy calculations
KW - dodecyl sulfate
KW - molecular dynamics simulations
KW - palmitic acid
KW - β-lactoglobulin
UR - http://www.scopus.com/inward/record.url?scp=85095726356&partnerID=8YFLogxK
U2 - 10.1080/07391102.2020.1844062
DO - 10.1080/07391102.2020.1844062
M3 - Artículo
C2 - 33155532
AN - SCOPUS:85095726356
SN - 0739-1102
VL - 40
SP - 3011
EP - 3023
JO - Journal of Biomolecular Structure and Dynamics
JF - Journal of Biomolecular Structure and Dynamics
IS - 7
ER -