Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031099 (periodontitis)
 12,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a rat periodontitis model, preinoculation with the Porphyromonas gingivalis HA2 binding domain for hemoglobin provided protection from disease. Protection was associated with induced anti-HA2 immunoglobulin G (IgG) humoral antibodies. The IgG subclass ratios suggested that relatively lower Th2/Th1-driven responses were directly associated with protection when rHA2 was administered in saline.
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PMID:Feasibility of an HA2 domain-based periodontitis vaccine. 1249 12

The gingipains have been implicated in the pathogenicity of Porphyromonas gingivalis, a major etiologic agent of chronic periodontitis. Mature gingipains often present as a membrane-bound glycosylated proteinase-adhesin complex comprising multiple adhesin domains (HA1 to -4) and a catalytic domain. Using recombinant adhesin domains, we were able to show that patients with chronic periodontitis produce significantly more immunoglobulin G reactive with gingipain domains than a corresponding group with healthy periodontium. Titers were predominantly directed toward the carbohydrate epitopes shared between the gingipains and the lipopolysaccharide of P. gingivalis with little recognition of the peptide backbone of the catalytic domains. Distribution of titers to peptide epitopes of the adhesin domains was as follows: HA4 approximately HA1 > HA3 >> HA2. No correlation was observed between markers of disease severity and titers to individual adhesins within the disease group. Posttreatment titers showed no change or a decrease in titers for the majority of patients except for titers to the HA2 domain which showed marked increases in a few responding patients. Since the HA2 domain is important in hemoglobin binding and acquisition of essential porphyrin, boosting titers of antibodies to this domain may have the potential to control the growth of this organism.
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PMID:Humoral responses to Porphyromonas gingivalis gingipain adhesin domains in subjects with chronic periodontitis. 1497 41

Porphyromonas gingivalis (P. gingivalis) is a major etiological agent in the development and progression of chronic periodontitis. It produces cysteine proteases (gingipains), including a lysine-specific gingipain and two arginine-specific gingipains. Heme binding and uptake are fundamental to the growth and virulence of P. gingivalis. The recombinant hemagglutinin 2 domain (rHA2) of gingipain binds hemin with high affinity. The aim of the present work was to identify the key residues involved in its hemin-binding activity. A functional rHA2 was expressed and bound to hemin-agarose, and then digested with endopeptidases. The peptides bound to hemin-agarose were identified by mass spectrometry and the amino acids were assessed by mutation and peptide binding inhibition analysis. The DHYAVMISK sequence was identified in peptides derived from both Asp-N and Lys-C endopeptidase digestions of rHA2. A monoclonal antibody, mAb QB, was produced and its epitope was associated with the DGFPGDHYAVMISK peptide within the HA2 domain. Hemin was shown to competitively inhibit the immunoreactivity of rHA2 or the peptide to mAb QB. The peptide DHYAVMISK inhibited hemin-binding activity; although, this inhibition was not seen when the peptide contained the H1001E mutation (DEYAVMISK). Based on these results, we propose that residue His1001 is involved in the hemin-binding mechanism of the P. gingivalis rHA2 and the peptide containing this residue, DHYAVMISK, may be an inhibitor of hemin binding.
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PMID:Identification of amino acid residues involved in hemin binding in Porphyromonas gingivalis hemagglutinin 2. 2583 25