title: Effects and Mechanism of Atmospheric-Pressure Dielectric Barrier Discharge Cold Plasma on Lactate Dehydrogenase (LDH) Enzyme.
abstract: Proteins are carriers of biological functions and the effects of atmospheric-pressure non-thermal plasmas on proteins are important to applications such as sterilization and plasma-induced apoptosis of cancer cells. Herein, we report our detailed investigation of the effects of helium-oxygen non-thermal dielectric barrier discharge (DBD) plasmas on the inactivation of lactate dehydrogenase (LDH) enzyme solutions. Circular dichroism (CD) and dynamic light scattering (DLS) indicate that the loss of activity stems from plasma-induced modification of the secondary molecular structure as well as polymerization of the peptide chains. Raising the treatment intensity leads to a reduced alpha-helix content, increase in the percentage of the beta-sheet regions and random sequence, as well as gradually decreasing LDH activity. However, the structure of the LDH plasma-treated for 300 seconds exhibits a recovery trend after storage for 24 h and its activity also increases slightly. By comparing direct and indirect plasma treatments, plasma-induced LDH inactivation can be attributed to reactive species (RS) in the plasma, especially ones with a long lifetime including hydrogen peroxide, ozone, and nitrate ion which play the major role in the alteration of the macromolecular structure and molecular diameter in lieu of heat, UV radiation, and charged particles.
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Zimu
authors.initials: Z
authors.lastname: Xu
authors.affiliation: 1] nstitute of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, Hefei 230031, P. R. China [2] Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Life Science, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Lili
authors.initials: L
authors.lastname: Ding
authors.affiliation: Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.affiliation: 1] nstitute of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, Hefei 230031, P. R. China [2] Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lan
authors.affiliation: 1] School of Life Science, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China [2] Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Xia
authors.affiliation: 1] nstitute of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, Hefei 230031, P. R. China [2] Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, People's Republic of China [3] Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei, Anhui Province 230026, People's Republic of China.
authors.forename: Zelong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Paul K
authors.initials: PK
authors.lastname: Chu
mesh_terms: D001274:Atmospheric Pressure; D002942:Circular Dichroism; D000067493:Dynamic Light Scattering; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D009566:Nitrates / Q000737:chemistry; D010126:Ozone / Q000737:chemistry; D058626:Plasma Gases / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013696:Temperature
chemical_list: D009566:Nitrates; D058626:Plasma Gases; D010126:Ozone; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase