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Author Spotlight: In Vitro Co-Culture System of Pine Shoots and Pinewood Nematode for Studying Host Volatile Response
Published on: September 27, 2024
Secondary structure changes induced by pulsed electric field affect antioxidant activity of pentapeptides from pine
Rong Liang1, Sheng Cheng2, Xiuying Wang2
1Analysis and Test Center, Dalian Polytechnic University, Dalian 116034, PR China; College of Food Science and Technology, Jilin University, Changchun 130062, PR China.
Abstract:
We used a pulsed electric field (PEF) to treat four pentapeptides with similar amino acid sequences (KCHKP, KCHQP, QCHKP, and QCHQP). We then evaluated antioxidant activity of the pentapeptides according to ferric reducing antioxidant power (FRAP) and hydroxyl radical scavenging capacity. Structures of the peptides were determined by high performance liquid chromatography (HPLC), mid-infrared (MIR), circular dichroism (CD) spectroscopy, and nuclear magnetic resonance (NMR). The results indicated that antioxidant activities of KCHQP and QCHKP were increased by PEF, whereas those of KCHKP and QCHQP were reduced. The basic structures and functional groups of peptides were unaffected. PEF treatment reduced the α-helix contents of KCHQP and QCHKP, but increased those of KCHKP and QCHQP. Moreover, the chemical shifts at 14.46 ppm, 8.22 ppm, 7.87 ppm, 7.24 ppm, and 6.13 ppm attributable to hydrogen atoms of QCHKP shifted to the right, but the active hydrogens of QCHQP were not affected by PEF.
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