What are lantibiotics?
Novacta Therapeutics product development activity is based on a class of compounds produced by bacteria called lantibiotics (lanthionine-containing antibiotics). Lantibiotics are highly post-translationally modified peptides containing a rare, dimeric amino acid called lanthionine. Due to the presence of these dimeric amino acids, the compounds have multiple ring structures.
Lantibiotics are a diverse compound class. Whilst all contain lanthionine moieties, their amino acid sequences and peptide length are variable, leading to quite different tertiary structures and biological activities.
Lantibiotic classes
The type A lantibiotics have a rod shaped structure and many have antibacterial activity mediated by formation of pores in the bacterial membrane. Novacta\\\'s programmes are based on type B lantibiotics which have a higher degree of cyclisation and are not pore forming. Within this broad family there are multiple sub-classes with different modes of action.
Antibacterial lantibiotics
Novacta\\\'s antibacterial lantibiotics act as inhibitors of cell wall biosynthesis by binding the biosynthetic intermediate lipid II. This is a validated target being the basis of the most rapidly growing antibacterial class, the glycopeptides. However, Novacta\\\'s compounds bind at a different binding site to the glycopeptides and there is no cross-resistance. Lipid II is considered an excellent target from a resistance perspective as it is not the product of a single gene and cannot readily mutate to a resistant form.
Antiviral lantibiotics
Novacta\\\'s antiviral lantibiotics are a distinct structural class with a quite different mode of action.
What are bacteriocins?
Bacteriocins are proteinaceous toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strains and are structurally, functionally and ecologically diverse. While traditionally bacteriocins are regarded as narrow spectrum antibiotics, Novacta is developing novel bacterocins that show the potential to be broad spectrum against gram -negative pathogens.
