Biotechnological production of an allergenic lipid transfer protein from Morus alba pollen

Abstract

Background/aim: Plant lipid transfer proteins (LTPs) assemble a family of small cationic proteins with an ability to bind and transport lipids as well as participate in various physiological processes including defense against phytopathogens. They also form one of the most clinically relevant classes of plant allergens. However, the allergenic properties of LTP in Morus alba (white mulberry) have not been studied. This study aimed to produce LTP found in M. alba pollens using recombinant DNA technology.Materials and methods: After total RNA isolation from M. alba pollens, a cDNA library was constructed. The sequence of the LTP gene amplified by PCR from this cDNA library was determined by sequencing and verified by the BLAST analysis. Then PCR product was cloned into the pQE- 2 vector. E.coli BL21 (DE3) cells were transformed with the vector for the recombinant protein synthesis. The recombinant allergen was isolated from transformants, and purified by Ni2+ affinity chromatography. rLTP was detected on SDS-PAGE gel and PVDF membrane by Coomassie blue staining and Western blotting, respectively.Results: Recombinant LTP was isolated for the first time from M. alba pollen. We identified an approximately 12-kDa protein as an allergen.Conclusion: Since LTP allergens from pollen and many foods are known to have a high prevalence in allergic patients, rLTP produced in this study may be used for diagnostic and therapeutic purposes in the future, following further clinical studies.