Alpha-like protein 2 (Alp2)

Alpha-like protein 2 (Alp2) is a key surface-anchored protein and virulence factor of Streptococcus agalactiae (Group B Streptococcus). It belongs to the Alpha-like protein family, which is defined by a mosaic structure consisting of a conserved N-terminal signal sequence and a series of large tandem repeats that facilitate bacterial adhesion to host epithelial cells. Alp2 is primarily expressed by GBS strains associated with invasive neonatal diseases, such as sepsis and meningitis, making it a critical target for diagnostic serotyping and therapeutic intervention. In the context of drug development, Alp2 is a primary antigen in recombinant protein-based vaccine candidates, where it elicits protective, opsonophagocytic antibodies. These vaccines aim to prevent maternal colonization and vertical transmission to newborns by neutralizing the bacteria's ability to adhere to and invade host tissues.

Other names

Alp2 proteinGroup B Streptococcus surface protein Alp2Alpha-like protein 2 (Alp2)alp2 gene product

Vaccine-induced or therapeutic antibodies bind to the Alp2 protein on the bacterial surface, facilitating opsonophagocytic killing by host immune cells and preventing bacterial attachment to host tissues.