Expression and Characterization of Rice-produced Recombinant Porcine Lactoferrin and its Antioxidant Activities
Kuan-Chih Lee1, Kun-Ting Hsieh1, Ray-Bin Chen1, Wei-Chih Lin2, Chang-Sheng Wang3, 4, Tzu-Tai Lee2, *, Liang-Jwu Chen1, 4, *
Identifiers and Pagination:Year: 2020
First Page: 94
Last Page: 106
Publisher ID: TOBIOTJ-14-94
Article History:Received Date: 15/03/2020
Revision Received Date: 12/5/2020
Acceptance Date: 22/5/2020
Electronic publication date: 24/08/2020
Collection year: 2020
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Lactoferrin (LF) exhibits multiple beneficial biological activities and thus has been used as a health food and additive. To broaden its application in the food industry, the porcine LF (pLF) gene has been engineered into rice to produce recombinant LF (rpLF) for use as a food additive. The iron-binding and antimicrobial activities of rpLF and its positive effects on early weaned piglets have been previously evaluated, yet several features, such as the signal peptide removal, glycosylation sites and antioxidant activity of rpLF, have not been fully characterized.
In this work, the rice-produced rpLF was purified and its biochemical structure and antioxidant activities characterized.
HPLC, Western blot, PAS/VVL/PNA staining, Edman degradation assay, MALDI-TOF, LC-MS/MS and antioxidant activity assays were performed.
The results showed that this purified rpLF is a mature form of LF; its signal peptide was correctly removed, and two N-glycosylation sites located at N365 and N472 were identified. The molecular mass heterogeneity of rpLF could be eliminated by treatment with PNGase glycosidase, suggesting that different degrees of N-glycosylation occur in rpLF. A series of assays including the iron chelating activity, reducing power assay, lipid peroxidase activity and radical-scavenging activity showed that the antioxidant activity of rice-produced rpLF was equivalent to that of bovine LF.
Rice-produced rpLF was correctly processed post-translationally and displayed antioxidant activity equivalent to that of bovine LF; thus, rice-produced rpLF can be recognized as a plant-based antioxidant to be used as a functional additive in animal feed and for the food industry.