Biomedical Applications of Lumazine Synthase.

Lumazine synthase (LS) is a family of enzyme involved in the penultimate step in the biosynthesis of riboflavin. Its enzymatic mechanism has been well defined, and many LS structures have been solved using X-ray crystallography or cryoelectron microscopy. LS is composed of homooligomers, which vary in size and subunit number, including pentamers, decamers, and icosahedral sixty-mers, depending on its species of origin. Research on LS has expanded beyond the initial focus on its enzymatic function to properties related to its oligomeric structure and exceptional conformational stability. These attributes of LS systems have now been repurposed for use in various biomedical fields. This review primarily focuses on the applications of LS as a flexible vaccine presentation system. Presentation of antigens on the surface of LS results in a high local concentration of antigens displayed in an ordered array. Such repetitive structures enable the cross-linking of B-cell receptors and result in strong immune responses through an avidity effect. Potential issues with the use of this system and corresponding solutions are also discussed with the objective of improved utilization of the LS system in vaccine development.