TY - JOUR
T1 - Investigating the Permeation Mechanism of Typical Phthalic Acid Esters (PAEs) and Membrane Response Using Molecular Dynamics Simulations
AU - Bao, Yiqiong
AU - Li, Mengrong
AU - Xie, Yanjie
AU - Guo, Jingjing
N1 - Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/6
Y1 - 2022/6
N2 - Phthalic acid esters (PAEs) are typical environmental endocrine disrupters, interfering with the endocrine system of organisms at very low concentrations. The plasma membrane is the first barrier for organic pollutants to enter the organism, so membrane permeability is a key factor affecting their biological toxicity. In this study, based on computational approaches, we investigated the permeation and intramembrane aggregation of typical PAEs (dimethyl phthalate, DMP; dibutyl phthalate, DBP; di‐2‐ethyl hexyl phthalate, DEHP), as well as their effects on membrane properties, and related molecular mechanisms were uncovered. Our results suggested that PAEs could enter the membrane spontaneously, preferring the headgroup‐acyl chain interface of the bilayer, and the longer the side chain (DEHP > DBP > DMP), the deeper the insertion. Compared with the shortest DMP, DEHP apparently increased membrane thickness, order, and rigidity, which might be due to its stronger hydrophobicity. Potential of means force (PMF) analysis revealed the presence of an energy barrier located at the water‐membrane interface, with a maximum value of 2.14 kcal mol−1 obtained in the DEHP‐system. Therefore, the difficulty of membrane insertion is also positively cor-related with the side‐chain length or hydrophobicity of PAE molecules. These findings will inspire our understanding of structure‐activity relationship between PAEs and their effects on membrane properties, and provide a scientific basis for the formulation of environmental pollution standards and the prevention and control of small molecule pollutants.
AB - Phthalic acid esters (PAEs) are typical environmental endocrine disrupters, interfering with the endocrine system of organisms at very low concentrations. The plasma membrane is the first barrier for organic pollutants to enter the organism, so membrane permeability is a key factor affecting their biological toxicity. In this study, based on computational approaches, we investigated the permeation and intramembrane aggregation of typical PAEs (dimethyl phthalate, DMP; dibutyl phthalate, DBP; di‐2‐ethyl hexyl phthalate, DEHP), as well as their effects on membrane properties, and related molecular mechanisms were uncovered. Our results suggested that PAEs could enter the membrane spontaneously, preferring the headgroup‐acyl chain interface of the bilayer, and the longer the side chain (DEHP > DBP > DMP), the deeper the insertion. Compared with the shortest DMP, DEHP apparently increased membrane thickness, order, and rigidity, which might be due to its stronger hydrophobicity. Potential of means force (PMF) analysis revealed the presence of an energy barrier located at the water‐membrane interface, with a maximum value of 2.14 kcal mol−1 obtained in the DEHP‐system. Therefore, the difficulty of membrane insertion is also positively cor-related with the side‐chain length or hydrophobicity of PAE molecules. These findings will inspire our understanding of structure‐activity relationship between PAEs and their effects on membrane properties, and provide a scientific basis for the formulation of environmental pollution standards and the prevention and control of small molecule pollutants.
KW - membrane response
KW - molecular dynamic simulations
KW - phthalic acid esters (PAEs)
KW - steered molecular dynamics simulation
KW - structure‐activity relationship
KW - umbrella sampling
UR - http://www.scopus.com/inward/record.url?scp=85132013217&partnerID=8YFLogxK
U2 - 10.3390/membranes12060596
DO - 10.3390/membranes12060596
M3 - Article
AN - SCOPUS:85132013217
SN - 2077-0375
VL - 12
JO - Membranes
JF - Membranes
IS - 6
M1 - 596
ER -