Premium
Study of the Enantioselective Interaction of Diclofop and Human Serum Albumin by Spectroscopic and Molecular Modeling Approaches In Vitro
Author(s) -
Zhang Ping,
Li Zhe,
Wang Xinru,
Shen Zhigang,
Wang Yao,
Yan Jin,
Zhou Zhiqiang,
Zhu Wentao
Publication year - 2013
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.22204
Subject(s) - chemistry , human serum albumin , enantiomer , enantioselective synthesis , fluorescence spectroscopy , molecular model , chirality (physics) , binding constant , circular dichroism , fluorescence , binding site , stereochemistry , organic chemistry , chromatography , biochemistry , physics , nambu–jona lasinio model , chiral symmetry breaking , quantum mechanics , quark , catalysis
In this contribution, the enantioselective interactions between diclofop (DC) and human serum albumin (HSA) were explored by steady‐state and 3D fluorescence, ultraviolet‐visible spectroscopy (UV‐vis), and molecular modeling . The binding constants between R‐DC and HSA were 0.9213 × 10 5 , 0.9118 × 10 5 , and 0.9009 × 10 5 L · mol ‐1 at 293, 303, 313 K, respectively. Moreover, the binding constants of S‐DC for HSA were 1.4766 × 10 5 , 1.2899 × 10 5 , and 1.0882 × 10 5 L · mol ‐1 at 293, 303, and 313 K individually. Such consequences markedly implied the binding between DC enantiomers and HSA were enantioselective with higher affinity for S‐DC. Steady‐state fluorescence study evidenced the formation of DC‐HSA complex and there was a single class of binding site on HSA. The thermodynamic parameters (ΔH, ΔS, ΔG) of the reaction clearly indicated that hydrophobic effects and H‐bonds contribute to the formation of DC‐HSA complex, which was in excellent agreement with molecular simulations. In addition, both site‐competitive replacement and molecular modeling suggested that DC enantiomers were located within the binding pocket of Sudlow's site II. Furthermore, the alterations of HSA secondary structure in the presence of DC enantiomers were verified by UV‐vis absorption and 3D fluorescence spectroscopy. This study can provide important insight into the enantioselective interaction of physiological protein HSA with chiral aryloxyphenoxy propionate herbicides and gives support to the use of HSA for chiral pesticides ecotoxicology and environmental risk assessment . Chirality 25 : 719–725 , 2013 . © 2013 Wiley Periodicals, Inc.