title: Correlation of haemagglutination activity with trypsin-like protease activity of Porphyromonas gingivalis.
abstract: Porphyromonas gingivalis is a Gram-negative anaerobic bacterium associated with various forms of periodontal disease. Several characteristics of P. gingivalis are thought to contribute to its pathogenicity; these include haemagglutination and trypsin-like protease activity. Previous studies suggest an association between haemagglutination and trypsin-like protease activity of P. gingivalis. To investigate this, two complementary quantitative experimental approaches were taken. Five independent mutants of P. gingivalis deficient in trypsin-like protease activity were shown to exhibit reduced haemagglutination activity. In addition, enhancers (cysteine and dithiothreitol) and inhibitors (N-ethylmaleimide, N-p-tosyl-L-lysine-chloromethyl ketone, and phenylmethylsulphonyl fluoride) of trypsin-like protease activity were shown, respectively, to significantly enhance and inhibit haemagglutination activity of washed, wild-type P. gingivalis cells (p less than 0.05, paired t-test). Statistical analysis indicated a strong correlation between haemagglutination and trypsin-like protease activity (r = 0.85, p less than 0.001, Spearman rank correlation). The effect of the protease enhancers and inhibitors on haemagglutination activity was specific for P. gingivalis, as they did not significantly change the haemagglutination activity of Fusobacterium nucleatum. These results suggest that the proteolytic site of the trypsin-like protease participates in haemagglutination activity of P. gingivalis.
authors.affiliation: Department of Stomatology, University of California, San Francisco 94143-0512.
authors.forename: C I
authors.initials: CI
authors.lastname: Hoover
authors.forename: C Y
authors.initials: CY
authors.lastname: Ng
authors.forename: J R
authors.initials: JR
authors.lastname: Felton
mesh_terms: D000818:Animals; D003545:Cysteine / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D016967:Fusobacterium nucleatum / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D005881:Gingiva / Q000382:microbiology; D006384:Hemagglutination / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008252:Macaca fascicularis; D009153:Mutagens / Q000494:pharmacology; D009604:Nitrosoguanidines / Q000494:pharmacology; D010641:Phenotype; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D016966:Porphyromonas gingivalis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology; D014357:Trypsin / Q000172:deficiency / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D009153:Mutagens; D009604:Nitrosoguanidines; D014107:Tosyllysine Chloromethyl Ketone; D010664:Phenylmethylsulfonyl Fluoride; D014357:Trypsin; D003545:Cysteine; D005033:Ethylmaleimide; D004229:Dithiothreitol