Cellular locations of proteinases and association with vesicles in porphyromonas gingivalis
- PDF / 1,093,457 Bytes
- 6 Pages / 591.92 x 838.534 pts Page_size
- 57 Downloads / 179 Views
september 24, 2010 Eur J Med Res (2010) 15: 397-402
397 © I. Holzapfel Publishers 2010
CEllulaR loCatIons of PRotEInasEs and assoCIatIon wItH VEsIClEs In P orPhyromonas gingivalis s. oishi 1, M. Miyashita 1, a. Kiso 1, Y. Kikuchi 2, o. ueda 2, K. Hirai 2, Y. shibata 3, s. fujimura 2 1 department
of oral Health Promotion, Graduate school of oral Medicine, 2department of oral Microbiology, 3 division of oral Health Promotion, Institute for oral science, Matsumoto dental university, shiojiri-nagano, Japan
Abstract we found that locations of arginine-specific gingipain (RGP) in the cellular fractions in the crude extract, envelope, vesicles, and culture supernatants were 48%, 16%, 17%, and 31%, respectively, and the corresponding values of lysine-specific gingipain (KGP) were 47%, 10%, 7%, and 36%, respectively. although the molecular mass of RGP in the culture supernatant had been determined as 43 kda, and that of KGP had been as 48 kda, molecular masses of both proteinases solubilized from the vesicles were estimated to be over 1,500 kda, since they eluted in the void volume of the column in the gel filtration on sephacryl s-300. there was no reduction of molecular size by the following treatment with sds, high-concentration naCl, or urea. Interestingly, the occurrence of the macromolecular forms could not observed in other enzymes tested such as monopeptidyl, dipeptidyl, and tripeptidyl peptidases, as well as alkaline phosphatase. therefore, occurrence of the macromolecular forms may be restricted to the proteinases. when the vesicle and culture supernatants containing free RGP and KGP were mixed and incubated, neither RGP nor KGP seemed to bind to vesicles. RGP bound to the vesicle was found to be more stable to heat treatment than the free form, suggesting that association of RGP with the vesicle caused heat stability of this enzyme. Key words: proteinase, enzyme, RGP, KGP, P. gingivalis , vesicle
IntRoduCtIon Gram-negative, black-pigmented obligatory anaerobes including Por phyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens have been implicated as etiological agents of human periodontitis, of which P. gingivalis is the most potent pathogen of this disease [1, 2, 3, 4]. RGP hydrolyses the peptide bonds of arginine-Xa.a. and KGP splits that of lysine-Ya.a., both are major proteinases of P. gingivalis, and these enzymes are considered to be important in the pathogenesis of periodontitis. the biochemical properties of these enzymes were described in the last decade and proteolytic enzymes have been implicated as important pathogenic factors [5, 6, 7]. However, obser-
vations from the biological aspects remain unsatisfactory. Vesicles have been thought to originate from the outer membranes of gram-negative bacterial species. toxic substances were found in the vesicles of ag gregatibacter (actinobacillus) actinomycetemcomitans and they were considered to be released into the crevicular environment, which may contribute to the pathogenesis of this species [8, 9]. Grenier and Mayrand described
Data Loading...
