Acta Phys. -Chim. Sin. ›› 2018, Vol. 34 ›› Issue (2): 185-193.doi: 10.3866/PKU.WHXB201707175

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Effects of Polyethyleneimine on the Conformation and Binding Capability of Human Serum Albumin

Bangzhi WEI,Zhiyong GUO,Fan WANG,Aimin HUANG,Lin MA*()   

  • Received:2017-06-19 Published:2017-11-13
  • Contact: Lin MA
  • Supported by:
    the National Natural Science Foundation of China(21373062)


For a better understanding of the cytotoxicity of polyethyleneimine (PEI), which has long been considered as the "golden standard" for polymeric gene delivery carriers, on the molecular basis, UV-Vis absorption, fluorescence, circular dichroism, dynamic light scattering and zeta-potential measurements were conducted to reveal the interaction between the PEI of average molecular weight 1.8 and 25 kDa (denoted as PEI1.8k and PEI25k, respectively) and human serum albumin (HSA). The effects of interactions on the conformation of HSA and its binding capability to the model compounds, 8-anilino-1-naphthalenesulfonic acid (ANS) and quercetin, were also evaluated. PEI was found to bind to HSA and induce an alteration in the secondary and tertiary structures of the protein and its binding capability toward small compounds. The complex formation with PEI resulted in a more compact and hydrophobic conformation of HSA, accompanying an increase in α-helix content in the case of PEI1.8k and PEI25k at low concentrations. The binding efficacy of ANS and quercetin to HSA was reduced by competitive binding with PEI, however increased by the conformational change of the protein. Higher-molecular-weight PEI was found to interact with HSA more favorably. It was also more efficient in perturbing the conformation and the binding capability of the protein.

Key words: Gene carrier, Polyethyleneimine, Human serum albumin, Conformation, Binding capability


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