Outer membrane porin

Outer membrane porins are a family of β-barrel proteins embedded in the outer membrane of Gram-negative bacteria, forming water-filled channels that allow passive diffusion of small, hydrophilic molecules such as nutrients, ions, and antibiotics. Different porins (e.g., OmpF, OmpC, OmpG, OprF) vary in channel size and substrate specificity. They are critical for bacterial homeostasis, environmental adaptation, and antibiotic susceptibility, and play roles in envelope integrity and cellular stress responses. Modulating porin expression or structure is a primary mechanism by which pathogenic bacteria develop resistance to antibiotics. Because "Outer membrane porin" refers to a large protein class encompassing many distinct but homologous proteins, rather than a single unique molecular target, the term is not specific enough for drug targeting without further clarification of the bacterial species and porin subtype.

Other names

OmpF (Outer membrane protein F)OmpC (Outer membrane protein C)OmpG (Outer membrane protein G)OprF (Pseudomonas Outer membrane protein F)Porin (generic protein class)

Alteration of porin expression or function (mutations or regulation) can decrease drug entry, conferring antibiotic resistance in bacteria. Use as entry pathways for antibiotics targeting the bacterial cytoplasm. Channel blocking by antibiotics or experimental inhibitors (less common, under exploration).