Synthesis, Characterization and Lipophilicity Study of Brucella abortus' Immunogenic Peptide Sequence That Can Be Used in the Future Vaccination Studies

Abstract

Brucellosis is primarily a zoonotic disease caused by members of the Brucella genus which consists of 11 recognized species based on pathogenicity and host preferences. Peptide vaccines are an alternative strategy to conventional vaccines based on the use of short peptide sequences and engineered to induce highly targeted immune responses, avoiding allergenic and/or reactogenic sequences. In this study, antigenic peptide sequence of Brucella abortus, WLAEIKQRSLMVHG, was chemically synthesized by adding tryptophan to the N-terminus of sequence, purified and characterized for the first time in the literature. Molecular weight of the peptide was determined by using LC-MS. A linear response (R-2 > 0.998) is observed for peptide in the range of 2-250 mu g/mL. The LOD and LOQ values are 0.08 and 0.27 mu g/kg respectively. Precision and accuracy ranges were found to be %RSD < 0.2 and 57.3-103.2%, respectively. Fluorescence property of the peptide was shown via fluorescence spectroscopy measurement. The 3D de novo structure of the peptide was predicted with PEP-FOLD server. According to the data obtained from the lipophilicity study (LogD(7.4) = - 3.093 +/- 0.195), the peptide can not cross the blood-brain barrier if applied via intravenously. This has shown us that peptide can be used as a peptide candidate at the vaccine studies. The production of antigenic peptides as in this study is the main component of the preparation of synthetic vaccine systems.