title: The cell extract of Porphyromonas gingivalis promotes attachment of Prevotella nigrescens cells to hydroxyapatite.
abstract: Large quantities of Prevotella nigrescens ATCC 25261 (P. nigrescens) cells adhere to hydroxyapatite (HA) treated with extract from Porphyromonas gingivalis 381 (Pg-Ext), but not to HA coated with human serum albumin (HSA) or human serum globulin (HSG). The duration of HA treatment with Pg-Ext and several other conditions were tested to determine the factors causing Pg-Ext to promote P. nigrescens cell adhesion. Pg-Ext adsorbed rapidly to HA in less than 5 min. The maximum adherence of P. nigrescens cells to HA was observed after treatment of HSA and HSG and then retreatment of HA with Pg-Ext. It was found that Pg-Ext heated at 80 degrees C for 30 min did not lose its propensity to promote attachment of P. nigrescens to HA and that it also remained stable at 4 degrees C for at least 6 days. The trypsin-like enzyme activity of Pg-Ext was also measured, with BAPNA as the substrate and commercially purchased trypsin as the standard, and was approximately 0.12 units/mg. These data suggest that the presence of Pg-Ext is one of the essential factors responsible for P. nigrescens cell attachment to apatitic surfaces, and that with its trypsin-like activity, Pg-Ext may be considered an extremely important substance for the establishment of P. nigrescens in the periodontal pocket and the development of periodontal disease.
authors.affiliation: Department of Bacteriology, Nihon University School of Dentistry, Tokyo 101-8310, Japan. hirano@dent.nihon-u.ac.jp
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hirano
authors.forename: Kouichiro
authors.initials: K
authors.lastname: Kuroda
authors.forename: Muneaki
authors.initials: M
authors.lastname: Tamura
authors.forename: Kunio
authors.initials: K
authors.lastname: Hayashi
mesh_terms: D000327:Adsorption; D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins; D003546:Cysteine Endopeptidases; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D010514:Periodontal Pocket / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000201:enzymology / Q000502:physiology*; D018720:Prevotella / Q000145:classification / Q000502:physiology*; D012709:Serum Albumin / Q000737:chemistry; D012712:Serum Globulins / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014357:Trypsin / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D012709:Serum Albumin; D012712:Serum Globulins; D017886:Durapatite; D014357:Trypsin; D003546:Cysteine Endopeptidases; C078912:prtT protein, Porphyromonas gingivalis