Full Length Research Paper

Primary purification of two antifungal proteins from leaves of the fig (Ficus carica L.)

Wei Yan³, Ming Zhao², Yan Ma², Ying-hong Pan^1* and Wen-xia Yuan²

¹Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, People’s Republic of China.

²College of Pu-erh Tea, Yunnan Agricultural University, Kunming 650201, People’s Republic of China.

³College of Life Science, Sichuan Normal University, Chengdu 610068, People’s Republic of China.

^*Corresponding author. E-mail: yhpan@caas.net.cn. Tel: +86-010-82105818. Fax: +86-010-82105817.

Abbreviations: TL, Thaumatin-like proteins; RIPs, ribosome-inactivating proteins; LTPs, lipid-transfer proteins; EDTA, ethylenediaminetetraacetic acid; DTT, DL-dithiothreitol; PVPP, polyvinylpyrrolidone; FPLC, fast protein liquid chromatography; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis; MALDI-TOF MS, matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Accepted 2 November, 2010

   Abstract

Low-molecular-weight extracts of fig (Ficus carica L.) leaves has antifungal and antibacterial activities against several types of microorganisms. In this work, two high-molecular-weight fractions with antifungal activity, termed figinI and figinII were obtained from leaves of fig using a procedure including ion-exchange chromatography (SP-Sepharose Fast Flow), hydrophobic-interaction chromatography (Phenyl Sepharose 6 Fast Flow and RESOURCE ISO) and ion-exchange chromatography (Mono S). By matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis (MALDI-TOF MS), the molecular mass of figinI was 21531Da and figinII was 31957Da. This is the first report on isolation of antifungal proteins from F. carica L., and it shows their potential for further investigation.

Key word: Fig, antifungal protein, chromatography, natural food preservative.