Title:A Novel Reversibly Glycosylated Polypeptide-2 of Bee Pollen from Rape (Brassica napus L.): Purification and Characterization
Volume: 28
Issue: 5
Author(s): Qi Zhang, Tian Sun, Xingxia Tuo, Yujin Li, Haixia Yang* Jianjun Deng*
Affiliation:
- College of Public Health, School of Medicine, Xi’an Jiaotong University, Xi’an,China
- School of Chemical Engineering, Northwest University, Xi’an,China
Keywords:
Reversibly glycosylated polypeptide, rape bee pollen, immunological histological chemistry, peptide mass fingerprinting,
MALDI-TOF-MS, Transmission Electron Microscope.
Abstract:
Background: Reversibly glycosylated polypeptide (RGP), a kind of hydrosoluble and
plasmodesmal-associated protein found in plants, plays a crucial role in the development of pollen.
Objective: A novel RGP 2 was isolated and identified from rape (Brassica napus L.) bee pollen.
Methods: RGP2 was isolated and purified by ion-exchange column and gel filtration chromatography,
and characterized by MALDI-TOF-MS, LC-MS, immunological histological chemistry, and
transmission electron microscope.
Results: Our results indicated that the RGP2 is an acidic protein (pI=5.46) with the molecular
weight 42388 Da. It contained 17 kinds of amino acids, among which aspartic acid had the highest
amount (71.56 mg/g). Homologous alignment of amino acid sequence results showed that RGP2
was 80.33%, 85.02%, 86.06%, and 88.93% identical to Arabidopsis thaliana RGP2 (AtRGP2),
Oryza sativa RGP (OsRGP), Triticum aestivum RGP (TaRGP), and Zea maize RGP (ZmRGP), respectively.
The localization results showed that RGP2 in rape anther existed in exine and intine of
anther cells of rape flower by immunological histological chemistry and the subcellular localization
identified that RGP2 appeared around the Golgi apparatus in cytoplasm by transmission electron
microscope.
Conclusion: RGP2 has a highly conserved sequence of amino acid residues and potential glycosylation
sites.