FOOD CHEMISTRY
·
2017
·
IF 4.529
Benguo Liu,Huizhi Xiao,Jiaqi Li,Sheng Geng,Hanjun Ma,Guizhao Liang
Trypsin is a kind of protease for digestion and food processing, whose activity can be inhibited by phenolic acids in plant foods. However, most reports explained the inhibitory difference of phenolic acids based on the number and position of substituent groups, which failed to reveal the comprehensive inhibitory mechanism. In this work, the inhibitory effects of 11 common phenolic acids on trypsin were investigated. Amongst the tested cinnamic and benzoic acid derivatives, caffeic acid and gallic acid showed the strongest anti-trypsin activity with a noncompetitive inhibition pattern, respectively. The fluorescence analysis displayed that both the quenching rate constant (K q ) and binding constant (K A ) of caffeic acid were higher than those of gallic acid. Molecular docking illustrated their different binding modes with trypsin. The ONIOM calculations revealed that the binding capacity of caffeic acid was higher than that of gallic acid, which could explain their difference in their inhibitory behaviors.
研究领域:
食品科学
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生物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2015
·Vol. 16
·期 8
·17999-18017
·
IF 2.862
Bin Li,Benguo Liu,Jiaqi Li,Huizhi Xiao,Junyi Wang,Guizhao Liang
Isoliquiritigenin (ILTG) possesses many pharmacological properties. However, its poor solubility and stability in water hinders its wide applications. The solubility of bioactive compounds can often be enhanced through preparation and delivery of various cyclodextrin (CD) inclusion complexes. The 6-O-α-d-maltosyl-β-CD (G2-β-CD), as one of the newest developments of CDs, has high aqueous solubility and low toxicity, especially stable inclusion characteristics with bioactive compounds. In this work, we for the first time construct and characterize the supermolecular structure of ILTG/G2-β-CD by scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD). The solubility of ILTG in water at 25 °C rises from 0.003 to 0.717 mg/mL by the encapsulation with G2-β-CD. Our experimental observations on the presence of the ILTG/G2-β-CD inclusion complex are further supported by the ONIOM(our Own N-layer Integrated Orbital molecular Mechanics)-based QM/MM (Quantum Mechanics/Molecular Mechanics) calculations, typically substantiating these supermolecular characteristics, such as detailed structural assignments, preferred binding orientations, selectivity, solvent effects, interaction energies and forces of the ILTG/G2-β-CD inclusion complex. Our results have elucidated how ILTG interacts with G2-β-CD, demonstrating the primary host-guest interactions between ILTG and G2-β-CD, characterized by hydrogen bonds, hydrophobic interactions, electrostatic forces, and conformational effects, are favored for the formation of the ILTG/G2-β-CD inclusion.Keywords:isoliquiritigenin;6-O-α-d-Maltosyl-β-CD;inclusion complex;ONIOM calculation
研究领域:
药学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2018
·
IF 3.52
Jiaqi Li,Sheng Geng,Benguo Liu,Huabin Wang,Guizhao Liang
The β-cyclodextrin (β-CD) can be used to remove bitter taste of protein hydrolysates, which is attributed to its interaction with hydrophobic amino acids included within peptides. But the corresponding mechanism has not been fully clarified. Herein, we systematically investigate the interaction between β-CD and three hydrophobic amino acids involving tryptophan (Trp), tyrosine (Tyr), and phenylalanine (Phe). We prove the formation of amino acid/β-CD supermolecular complexes determined by FS, UV, IR, DSC and NMR, manifesting that no new chemical bond is formed in these complexes. The theoretical interaction conformations are given by molecule docking and further supported by ONIOM (our Own N-layer Integrated Orbital molecular Mechanics) calculations, with the consideration of structural assignments, binding orientations, solvent effects, interaction energies and main forces to form these complexes. Molecular docking results suggest that the hydrophobic amino acids prefer to interact with β-CD by their aromatic ring, meaning hydrophobic interactions are main forces for them entering into the cavity of β-CD. ONIOM-based calculations provide a number of quantum-chemical parameters to confirm our experimental results; meanwhile, to demonstrate that H-bonds play an important role in maintaining the stability of three amino acid/β-CD complexes. This work is help for demonstrating the interaction mechanism of amino acid/β-CD supermolecular system, and guiding how to remove bitterness or undesirable taste of bioactive peptides , even other interested molecules.
研究领域:
食品科学
·
生物化学
·
理论计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）