title: D-Galactose as an autoinducer 2 inhibitor to control the biofilm formation of periodontopathogens.
abstract: Autoinducer 2 (AI-2) is a quorum sensing molecule to which bacteria respond to regulate various phenotypes, including virulence and biofilm formation. AI-2 plays an important role in the formation of a subgingival biofilm composed mostly of Gram-negative anaerobes, by which periodontitis is initiated. The aim of this study was to evaluate D-galactose as an inhibitor of AI-2 activity and thus of the biofilm formation of periodontopathogens. In a search for an AI-2 receptor of Fusobacterium nucleatum, D-galactose binding protein (Gbp, Gene ID FN1165) showed high sequence similarity with the ribose binding protein (RbsB), a known AI-2 receptor of Aggregatibacter actinomycetemcomitans. D-Galactose was evaluated for its inhibitory effect on the AI-2 activity of Vibrio harveyi BB152 and F. nucleatum, the major coaggregation bridge organism, which connects early colonizing commensals and late pathogenic colonizers in dental biofilms. The inhibitory effect of D-galactose on the biofilm formation of periodontopathogens was assessed by crystal violet staining and confocal laser scanning microscopy in the absence or presence of AI-2 and secreted molecules of F. nucleatum. D-Galactose significantly inhibited the AI-2 activity of V. harveyi and F. nucleatum. In addition, D-galactose markedly inhibited the biofilm formation of F. nucleatum, Porphyromonas gingivalis, and Tannerella forsythia induced by the AI-2 of F. nucleatum without affecting bacterial growth. Our results demonstrate that the Gbp may function as an AI-2 receptor and that galactose may be used for prevention of the biofilm formation of periodontopathogens by targeting AI-2 activity.
authors: Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea.
authors: Eun-Ju
authors: EJ
authors: Ryu
authors: Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea.
authors: Jaehyun
authors: J
authors: Sim
authors: Department of Bioinformatics and Life Science, Soongsil University, Seoul, 06978, Republic of Korea.
authors: Jun
authors: J
authors: Sim
authors: Department of Bioinformatics and Life Science, Soongsil University, Seoul, 06978, Republic of Korea.
authors: Julian
authors: J
authors: Lee
authors: Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea. bongchoi@snu.ac.kr.|Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea. bongchoi@snu.ac.kr.
authors: Bong-Kyu
authors: BK
authors: Choi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D016967:Fusobacterium nucleatum / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D005690:Galactose / Q000378:metabolism / Q000494:pharmacology*; D006714:Homoserine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D007783:Lactones / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D010518:Periodontitis / Q000382:microbiology*; D033902:Periplasmic Binding Proteins / Q000235:genetics / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000187:drug effects* / Q000502:physiology; D014733:Vibrio / Q000187:drug effects / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D002135:Calcium-Binding Proteins; D007783:Lactones; D009004:Monosaccharide Transport Proteins; C091088:N-octanoylhomoserine lactone; D033902:Periplasmic Binding Proteins; C023550:galactose-binding protein; D006714:Homoserine; D005690:Galactose
keywords: AI-2 inhibitor; D-galactose; biofilm; periodontopathogens; quorum sensing