Genotype characterization of histaminase enzyme from grass pea (Lathyrus sativus) for treatment and diagnosis purposes

Histamine is a biological amine that plays a role in various diseases such as allergic rhinitis, conjunctivitis, urticaria and atopic dermatitis, as well as in the development of anaphylaxis and allergic asthma. Medicinal plants have long been used in the treatment of different diseases. Due to the extensive use of this enzyme in the treatment of histamine-induced diseases in humans and animals, this study aimed at cloning and characterization of the DAO gene in this Iranian native grass pea plant (Lathyrus sativus). For this purpose, the extraction of mRNA from native seedling of Fars province done and followed by cDNA synthesis for the amplification of the histaminease gene using primers designed. Then, the cloning of the gene performed after double digestion of the gene and the pQE-80L vector. Finally, the recombinant vector transferred to Escherichia colistrain XL1-Blue. Cloning accuracy was confirmed by enzymatic digestion and sequencing. After nucleotide sequencing, the corresponding mRNA gene with 1995 bp length was deposited in GenBank database under accession number KR063661. Also, its protein sequence was registered in the GenBank under accession number ALE71304. The evaluation of the three-dimensional structure of the native histaminase enzyme and its phylogenetic study was performed based on the well-known sequences in this study Which showed the highest genetic (94%) and protein (96%) similarity to chickpea (Pisium sativum). The recombinant plasmid was produced in the future can be used in expression systems to produce mass enzymes for the therapeutic properties of this unique enzyme.