title: Suppression of pathogenicity of Porphyromonas gingivalis by newly developed gingipain inhibitors.
abstract: Arg-gingipain (Rgp) and Lys-gingipain (Kgp) are cysteine proteinases produced by Porphyromonas gingivalis, a major etiological bacterium of periodontal diseases. Here we show a series of small peptide analogs able to inhibit either Rgp or Kgp, which are synthesized on the basis of the cleavage site specificity of human salivary histatins by each enzyme. Among this series of compounds, carbobenzoxy-Lys-Arg-CO-Lys-N-(CH2)2 (KYT-1) and carbobenzoxy-Glu(NHN(CH3)Ph)-Lys-CO-NHCH2Ph (KYT-36) were found to be the most potent inhibitors of Rgp and Kgp, respectively, with Ki values of 10(-11) to 10(-10) M order. Both inhibitors exhibited slight or no inhibition on mammalian proteinases such as trypsin and cathepsins B, L, and H. All of the virulence induced by the culture supernatant of P. gingivalis tested, including the degradation of various host proteins such as human type I collagen, immunoglobulins, fibronectin, and fibrinogen, disruption of the bactericidal activity of polymorphonuclear leukocytes, and enhancement of the vascular permeability, were strongly inhibited by a combined action of both inhibitors. The functions essential for the bacterium to grow and survive in the periodontal pocket, such as coaggregation and acquisition of amino acids, were also strongly inhibited by the combined action of both inhibitors. The disruption of the adhesion and viability of human fibroblasts and hemagglutination by the organism were strongly suppressed by a single use of KYT-1. These results thus indicate that the newly developed KYT-1 and KYT-36 both should provide a broader application in studies of this important class of enzymes and facilitate the development of new approaches to periodontal diseases.
authors.affiliation: Department of Pharmacology, Graduate School of Dental Science, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Atsuyo
authors.initials: A
authors.lastname: Baba
authors.forename: Naoko
authors.initials: N
authors.lastname: Abe
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Takii
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tsukuba
authors.forename: Shinji
authors.initials: S
authors.lastname: Okazaki
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Suda
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Asao
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D018829:Adhesins, Bacterial; D002448:Cell Adhesion; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology / Q000382:microbiology; D000080867:Gingipain Cysteine Endopeptidases; D005881:Gingiva / Q000166:cytology / Q000382:microbiology; D006386:Hemagglutination Tests; D006388:Hemagglutinins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000472:pathogenicity*
chemical_list: D018829:Adhesins, Bacterial; D004791:Enzyme Inhibitors; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins; D003546:Cysteine Endopeptidases