Prediction of C-glycosylated apigenin （vitexin） biosynthesis in Ficus deltoidea based on plant proteins identified by LC-MS/MS

作     者：Farah Izana Abdullah Lee Suan Chua Zaidah Rahmat 

作者机构：Metabolites Profiling Laboratory Institute of Bioproduct Development Universiti Teknologi Malaysia 81310 UTM Skudai Johor BahruJohor Malaysia Department of Bioprocess and Polymer Engineering Faculty of Chemical and Energy Engineering Universiti Teknologi Malaysia 81310UTM Skudai Johor Bahru Johor Malaysia Department of Biotechnology and Medical Engineering Faculty of Biosciences & Medical Engineering Universiti Teknologi Malaysia81310 UTM Skudai Johor Bahru Johor Malaysia 

出 版 物：《Frontiers in Biology》 (生物学前沿（英文版）)

年 卷 期：2017年第12卷第6期

页      面：448-458页

核心收录：

学科分类：0710[理学-生物学] 0831[工学-生物医学工程（可授工学、理学、医学学位）] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 1001[医学-基础医学(可授医学、理学学位)] 07[理学] 09[农学] 0836[工学-生物工程] 0713[理学-生态学] 

基　　金：the Ministry of Higher Education for their financial support under the HiCoE 

主　　题：C-glycosylation vitexin apigenin 8-C glucoside proteins peptides LC-MS/MS 

摘      要：Plant secondary metabolites act as defence molecules to protect plants from biotic and abiotic stresses. In particular, C-glycosylated flavonoids are more stable and reactive than their O-glycosylated counterparts. Therefore, vitexin (apigenin 8-C glucoside) present in Ficus deltoidea is well-known for its antioxidant, anti-inflammatory, and antidiabetic properties. Phenol based extraction was used to extract proteins (0.05% yield) with less plant pigments. This can be seen from clear protein bands in gel electrophoresis. In-gel trypsin digestion was subsequently carried out and analysed for the presence of peptides by LC-MS/MS. Thirteen intact proteins are identified on a 12% polyacrylamide gel. The mass spectra matching was found to have 229 proteins, and 11.4% of these were involved in secondary metabolism. Proteins closely related to vitexin biosynthesis are listed and their functions are explained mechanistically. Vitexin synthesis is predicted to involve plant polyketide chalcone synthase, isomerization by chalcone isomerase, oxidation by cytochrome P450 to convert flavanone to flavone, and transfer of sugar moiety by C-glycosyltransferase, followed by dehydration to produce flavone-8-C-glucosides. Phenol based extraction, followed by gel electrophoresis and LC-MS/MS could identify proteome explaining vitexin biosynthesis in F. deltoidea. Many transferases including β-1,3-galactosyltransferase 2 and glycosyl hydrolase family 10 protein were detected in this study. This explains the importance of transferase family proteins in Cglycosylated apigenin biosynthesis in medicinal plant.